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Search: a328392 -id:a328392
Displaying 1-7 of 7 results found.
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A327860
Arithmetic derivative of the primorial base exp-function: a(n) = A003415(A276086(n)).
+10
79
0, 1, 1, 5, 6, 21, 1, 7, 8, 31, 39, 123, 10, 45, 55, 185, 240, 705, 75, 275, 350, 1075, 1425, 3975, 500, 1625, 2125, 6125, 8250, 22125, 1, 9, 10, 41, 51, 165, 12, 59, 71, 247, 318, 951, 95, 365, 460, 1445, 1905, 5385, 650, 2175, 2825, 8275, 11100, 30075, 4125, 12625, 16750, 46625, 63375, 166125, 14, 77, 91, 329, 420
(list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
COMMENTS
Are there any other fixed points after 0, 1, 7, 8 and 2556? (A328110, see also A351087 and A351088).
Out of the 30030 initial terms, 19220 are multiples of 5. (See A327865).
Proof that a(n) is even if and only if n is a multiple of 4: Consider Charlie Neder's Feb 25 2019 comment in A235992. As A276086 is never a multiple of 4, and as it toggles the parity, we only need to know when A001222(A276086(n)) = A276150(n) is even. The condition for that is given in the latter sequence by David A. Corneth's Feb 27 2019 comment. From this it also follows that A166486 gives similarly the parity of terms of A342002, A351083 and A345000. See also comment in A327858. - Antti Karttunen, May 01 2022
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..2310
Antti Karttunen, Data supplement: n, a(n) computed for n = 0..30030
Index entries for sequences related to primorial base
FORMULA
a(n) = A003415(A276086(n)).
a(A002110(n)) = 1 for all n >= 0.
From Antti Karttunen, Nov 03 2019: (Start)
Whenever A329041(x,y) = 1, a(x + y) = A003415(A276086(x)*A276086(y)) = a(x)*A276086(y) + a(y)*A276086(x). For example, we have:
a(n) = a(A328841(n)+A328842(n)) = A329031(n)*A328572(n) + A329032(n)*A328571(n).
A051903(a(n)) = A328391(n).
A328114(a(n)) = A328392(n).
(End)
From Antti Karttunen, May 01 2022: (Start)
a(n) = A328572(n) * A342002(n).
For all n >= 0, A000035(a(n)) = A166486(n). [See comments]
(End)
EXAMPLE
2556 has primorial base expansion [1,1,1,1,0,0] as 1*A002110(5) + 1*A002110(4) + 1*A002110(3) + 1*A002110(2) = 2310 + 210 + 30 + 6 = 2556. That in turn is converted by A276086 to 13^1 * 11^1 * 7^1 * 5^1 = 5005, whose arithmetic derivative is 5' * 1001 + 1001' * 5 = 1*1001 + 311*5 = 2556, thus 2556 is one of the rare fixed points (A328110) of this sequence.
MATHEMATICA
Block[{b = MixedRadix[Reverse@ Prime@ Range@ 12]}, Array[Function[k, If[# < 2, 0, # Total[#2/#1 & @@@ FactorInteger[#]] ] &@ Abs[Times @@ Power @@@ # &@ Transpose@{Prime@ Range@ Length@ k, Reverse@ k}]]@ IntegerDigits[#, b] &, 65, 0]] (* Michael De Vlieger, Mar 12 2021 *)
PROG
(PARI)
A003415(n) = {my(fac); if(n<1, 0, fac=factor(n); sum(i=1, matsize(fac)[1], n*fac[i, 2]/fac[i, 1]))}; \\ From A003415
A276086(n) = { my(i=0, m=1, pr=1, nextpr); while((n>0), i=i+1; nextpr = prime(i)*pr; if((n%nextpr), m*=(prime(i)^((n%nextpr)/pr)); n-=(n%nextpr)); pr=nextpr); m; };
A327860(n) = A003415(A276086(n));
(PARI) A327860(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= (p^e); s += (e/p); n = n\p; p = nextprime(1+p)); (s*m); }; \\ (Standalone version) - Antti Karttunen, Nov 07 2019
CROSSREFS
Cf. A002110 (positions of 1's), A003415, A048103, A276086, A327858, A327859, A327865, A328110 (fixed points), A328233 (positions of primes), A328242 (positions of squarefree terms), A328388, A328392, A328571, A328572, A329031, A329032, A329041, A342002.
Cf. A345000, A351074, A351075, A351076, A351077, A351080, A351083, A351084, A351087 (numbers k such that a(k) is a multiple of k), A351088.
Coincides with A329029 on positions given by A276156.
Cf. A166486 (a(n) mod 2), A353630 (a(n) mod 4).
Cf. A267263, A276150, A324650, A324653, A324655 for omega, bigomega, phi, sigma and tau applied to A276086(n).
Cf. also A351950 (analogous sequence).
KEYWORD
nonn,base,easy,look
AUTHOR
Antti Karttunen, Sep 30 2019
EXTENSIONS
Verbal description added to the definition by Antti Karttunen, May 01 2022
STATUS
approved
A328114
Maximal digit value used when n is written in primorial base (cf. A049345).
+10
54
0, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3
(list; graph; refs; listen; history; text; internal format)
OFFSET
0,5
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..30030
Index entries for sequences related to primorial base
FORMULA
a(n) = A051903(A276086(n)).
a(A276156(n)) = 1 for all n >= 1.
a(n) <= A276150(n) for all n >= 0.
From Antti Karttunen, Oct 29 2019: (Start)
a(n) = A061395(A328835(n)).
For n >= 1, a(n) < A000040(A235224(n)) and a(n) <= 1 + A328391(n).
For all n >= 1, a(n) = 1+A051903(A328572(n)).
a(A276086(n)) = A328389(n), a(A276087(n)) = A328394(n), a(A328403(n)) = A328398(n).
a(A327860(n)) = A328392(n), a(A003415(n)) = A328390(n), a(A328316(n)) = A328322(n).
(End)
EXAMPLE
For n = 2105, which could be expressed in primorial base for example as "T0021" (where T here stands for the digit value ten), or maybe more elegantly as [10,0,0,2,1] as 2105 = 10*A002110(4) + 2*A002110(1) + 1*A002110(0). The maximum value of these digits is 10, thus a(2105) = 10.
MATHEMATICA
With[{b = MixedRadix[Reverse@ Prime@ Range@ 20]}, Array[Max@ IntegerDigits[#, b] &, 105, 0]] (* Michael De Vlieger, Oct 30 2019 *)
PROG
(PARI) A328114(n) = { my(i=0, m=0, pr=1, nextpr); while((n>0), i=i+1; nextpr = prime(i)*pr; if((n%nextpr), m = max(m, (n%nextpr)/pr); n-=(n%nextpr)); pr=nextpr); (m); };
(PARI) A328114(n) = { my(s=0, p=2); while(n, s = max(s, (n%p)); n = n\p; p = nextprime(1+p)); (s); }; \\ (Faster, no unnecessary construction of primorials) - Antti Karttunen, Oct 29 2019
CROSSREFS
Cf. A002110, A049345, A051903, A061395, A276086, A267263, A276150, A327969, A328316, A328322, A328389, A328390, A328392, A328394, A328398, A328403, A328835.
Cf. A276156 (indices of terms < 2).
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 12 2019
STATUS
approved
A328389
Maximal digit value in primorial base expansion of A276086(n): a(n) = A328114(A276086(n)).
+10
13
1, 1, 1, 1, 1, 3, 2, 2, 2, 1, 2, 3, 4, 3, 2, 5, 2, 2, 4, 2, 5, 4, 5, 10, 6, 6, 8, 6, 5, 9, 1, 2, 3, 2, 2, 4, 2, 2, 3, 1, 3, 3, 5, 4, 3, 5, 7, 4, 4, 8, 3, 3, 4, 9, 9, 8, 7, 11, 4, 8, 3, 3, 4, 4, 3, 4, 2, 2, 3, 7, 10, 10, 5, 4, 6, 3, 8, 9, 7, 5, 10, 10, 10, 8, 5, 5, 8, 6, 9, 7, 4, 4, 6, 9, 4, 7, 8, 5, 3, 5, 7, 4, 7, 7, 11, 9
(list; graph; refs; listen; history; text; internal format)
OFFSET
0,6
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..32589
Index entries for sequences related to primorial base
FORMULA
a(n) = A328114(A276086(n)).
a(n) = A051903(A276087(n)).
PROG
(PARI)
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A328114(n) = { my(s=0, p=2); while(n, s = max(s, (n%p)); n = n\p; p = nextprime(1+p)); (s); };
A328389(n) = A328114(A276086(n));
CROSSREFS
Cf. A002110, A051903, A143293, A276086, A276087, A328114, A328322, A328390, A328391, A328392, A328395.
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 15 2019
STATUS
approved
A328391
Maximal exponent in the prime factorization of A327860(n): a(n) = A051903(A327860(n)).
+10
13
0, 0, 1, 1, 1, 0, 1, 3, 1, 1, 1, 1, 2, 1, 1, 4, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 0, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 3, 1, 1, 1, 1, 1, 2, 2, 7, 2, 2, 2, 3, 3, 3, 3, 3, 3, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2
(list; graph; refs; listen; history; text; internal format)
OFFSET
1,8
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..30030
Index entries for sequences related to primorial base
FORMULA
a(n) = A051903(A327860(n)) = A051903(A003415(A276086(n))).
a(A002110(n)) = 0 for all n >= 0.
For all n >= 1, a(n) >= A328114(n)-1. [Because arithmetic derivative will decrease the maximal prime exponent (A051903) of its argument by at most one]
PROG
(PARI)
A051903(n) = if((1==n), 0, vecmax(factor(n)[, 2]));
A327860(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= (p^e); s += (e/p); n = n\p; p = nextprime(1+p)); (s*m); };
A328391(n) = A051903(A327860(n));
CROSSREFS
Cf. A002110, A003415, A051903, A276086, A327860, A327969, A328114, A328388, A328389, A328390, A328392.
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 15 2019
STATUS
approved
A328390
Maximal digit value in primorial base expansion of the arithmetic derivative of n: a(n) = A328114(A003415(n)).
+10
11
0, 1, 1, 2, 1, 2, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 4, 2, 2, 1, 2, 2, 2, 4, 1, 1, 1, 1, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 3, 1, 4, 1, 3, 2, 2, 3, 4, 1, 3, 2, 3, 3, 1, 1, 3, 1, 1, 3, 6, 3, 2, 1, 2, 4, 4, 1, 5, 1, 1, 4, 3, 3, 2, 1, 5, 3, 2, 1, 4, 3, 2, 1, 4, 1, 4, 3, 3, 2, 3, 4, 2, 1, 2, 2, 4, 1, 3, 1, 5, 2
(list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..30030
Index entries for sequences related to primorial base
FORMULA
a(n) = A328114(A003415(n)).
a(n) = A051903(A327859(n)).
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A328114(n) = { my(s=0, p=2); while(n, s = max(s, (n%p)); n = n\p; p = nextprime(1+p)); (s); };
A328390(n) = A328114(A003415(n));
CROSSREFS
Cf. A003415, A051903, A327859, A328114, A328389, A328391, A328392.
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 15 2019
STATUS
approved
A342005
a(n) = A342004(A276086(n)).
+10
6
1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1
(list; graph; refs; listen; history; text; internal format)
OFFSET
0
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..65537
Index entries for characteristic functions
Index entries for sequences related to primorial base
FORMULA
a(n) = 1 if A328391(n) < A328114(n), otherwise 0.
PROG
(PARI)
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A342005(n) = A342004(A276086(n)); \\ Uses also code from A342004.
CROSSREFS
Cf. A003415, A276086, A328114, A328391, A328392, A342004, A342006 (positions of zeros).
KEYWORD
nonn
AUTHOR
Antti Karttunen, Mar 03 2021
STATUS
approved
A328396
Lexicographically earliest infinite sequence such that a(i) = a(j) => f(i) = f(j) for all i, j, where f(n) = A046523(A276086(A003415(A276086(n)))).
+10
4
1, 2, 2, 3, 2, 4, 2, 5, 5, 5, 6, 7, 3, 8, 7, 9, 5, 10, 11, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 2, 22, 3, 8, 23, 24, 25, 26, 11, 6, 27, 28, 29, 24, 11, 30, 31, 32, 27, 33, 10, 34, 35, 36, 37, 38, 39, 19, 40, 41, 3, 42, 43, 44, 25, 45, 46, 11, 9, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 4, 69, 70, 71, 72, 73, 74, 32
(list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
Restricted growth sequence transform of function f(n) = A278226(A327860(n)) = A046523(A276086(A003415(A276086(n)))).
For all i, j: a(i) = a(j) => A328392(i) = A328392(j).
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..30030
PROG
(PARI)
up_to = 30030;
rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om, invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om, invec[i], i); outvec[i] = u; u++ )); outvec; };
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
Aux328396(n) = A046523(A276086(A003415(A276086(n))));
v328396 = rgs_transform(vector(1+up_to, n, Aux328396(n-1)));
A328396(n) = v328396[1+n];
CROSSREFS
Cf. A003415, A046523, A276086, A327860, A328392.
Cf. also A278226, A286626, A328388, A328395.
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 15 2019
STATUS
approved
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Last modified November 27 16:51 EST 2024. Contains 378160 sequences.
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