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Search: a090457 -id:a090457
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Difference between numbers of binary 1's of n and binary 1's of n-th prime.
+10
6
0, -1, 0, -2, -1, -1, 1, -2, -2, -2, -2, -1, 0, -1, -1, -3, -3, -3, 0, -2, 0, -2, 0, -2, 0, -1, -1, -2, -1, 0, -2, -2, -1, -2, -1, -3, -2, -1, -1, -3, -2, -2, -3, 0, 0, -1, 0, -5, -2, -2, -1, -4, -1, -3, 3, -1, 0, -1, 1, 0, 0, 1, 1, -5, -3, -4, -2, -2, -3, -3, 0, -4, -4, -3
OFFSET
1,4
LINKS
FORMULA
a(n) = A000120(n) - A014499(n);
a(A071600(n)) = a(A049084(A072439(n))) = 0.
a(A049084(A090456(n))) < 0.
a(A049084(A090457(n))) > 0.
MATHEMATICA
Table[DigitCount[n, 2, 1]-DigitCount[Prime[n], 2, 1], {n, 80}] (* Harvey P. Dale, Aug 08 2013 *)
KEYWORD
sign,base
AUTHOR
Reinhard Zumkeller, Dec 01 2003
EXTENSIONS
Definition clarified by Harvey P. Dale, Aug 08 2013
STATUS
approved
Primes p(k) having a smaller sum of digits than k.
+10
4
11, 13, 23, 61, 101, 103, 107, 109, 151, 163, 211, 223, 227, 241, 251, 271, 311, 313, 317, 331, 337, 347, 401, 421, 431, 433, 443, 461, 503, 509, 521, 523, 701, 911, 1009, 1013, 1021, 1031, 1033, 1051, 1061, 1063, 1103, 1109, 1117, 1123, 1129, 1151
OFFSET
1,1
COMMENTS
A090431(a(n)) > 0.
LINKS
MATHEMATICA
Select[Prime[Range[200]], Total[IntegerDigits[#]]<Total[IntegerDigits[ PrimePi[ #]]]&] (* Harvey P. Dale, Mar 05 2017 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Dec 01 2003
STATUS
approved
Primes prime(k) having more binary 1's than k.
+10
4
3, 7, 11, 13, 19, 23, 29, 31, 37, 43, 47, 53, 59, 61, 71, 79, 89, 101, 103, 107, 109, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 199, 223, 227, 229, 233, 239, 241, 251, 263, 271, 311, 313, 317, 331, 337, 347, 349, 359, 367, 373, 379, 383
OFFSET
1,1
LINKS
FORMULA
A090455(a(n)) < 0.
MATHEMATICA
Select[Prime[Range[100]], Differences[DigitCount[{PrimePi[#], #}, 2, 1]][[1]] > 0 &] (* Amiram Eldar, Apr 23 2022 *)
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Dec 01 2003
STATUS
approved

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