[go: up one dir, main page]

login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Revision History for A369657 (Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing entries 1-10 | older changes
#18 by N. J. A. Sloane at Wed Feb 14 14:26:31 EST 2024
STATUS

editing

approved

#17 by N. J. A. Sloane at Wed Feb 14 14:26:22 EST 2024
COMMENTS

a(n) = 0 for most n divisible by 4, except for n = 64, 96, 128, 144, 160, 192, 216, 224, 240, 256, ... These exceptions include all proper multiples of 32 but also some other multiples of 4: 9*16, 27*8, 15*16, 21*16, ...

a(n) = 0 also for some n not a multiple of 4, namely 18*(6k + 1) for all k >= 0 except 2604, 18229, 33854, ... and 27*(4k + 1) for k >= 0 different from 101, 182, 236, ..., and others.

a(n) = 48 for all numbers of the form 32*p where p is prime, and for n = 171. (Is Are there any otherothers?) This is by far the most frequent nonzero value, : it can be seen as a horizontal line in the graph of the sequence.

STATUS

proposed

editing

Discussion
Wed Feb 14
14:26
N. J. A. Sloane: edited
#16 by M. F. Hasler at Wed Feb 14 14:01:52 EST 2024
STATUS

editing

proposed

#15 by M. F. Hasler at Wed Feb 14 13:56:54 EST 2024
COMMENTS

a(n) = 0 also for some n not multiple of 4, namely 918*(12k 6k + 21), 9 for all k >= 0 except 2604, 18229, 33854, ... and 27*(12k 4k + 31), for k >= 0 different from 101, 182, 236, ..., and others.

STATUS

proposed

editing

Discussion
Wed Feb 14
14:01
M. F. Hasler: I think you're right. Maybe because offset was changed in 2008: https://oeis.org/history?seq=A067076&start=80
#14 by Thomas Scheuerle at Wed Feb 14 13:50:53 EST 2024
STATUS

editing

proposed

#13 by M. F. Hasler at Wed Feb 14 13:49:20 EST 2024
COMMENTS

a(n) = 0 for most n divisible by 4, except for n = 64, 96, 128, 144, 160, 192, 216, 224, 240, 256, ...: these appear to These exceptions include all proper multiples of 32 but also some other multiples of 4: 9*16, 27*8, 15*16, 21*16, ...

a(n) = 0 also for some non-multiples n not multiple of 4, namely 9*(12k + 2), 9*(12k + 3), and others.

#12 by Thomas Scheuerle at Wed Feb 14 13:48:59 EST 2024
FORMULA

a(9*prime(n)) = 63*A067076A086801(n-1) for n > 1. - Thomas Scheuerle, Feb 14 2024

CROSSREFS
#11 by Thomas Scheuerle at Wed Feb 14 13:37:36 EST 2024
FORMULA

a(9*prime(n)) = 6*A067076(n-1) for n > 1. - Thomas Scheuerle, Feb 14 2024

CROSSREFS
STATUS

proposed

editing

Discussion
Wed Feb 14
13:46
Thomas Scheuerle: Are some formulas in A067076 with wrong offset ?
" a(n) = A006254(n+1) - 2 = A086801(n)/2."
#10 by M. F. Hasler at Wed Feb 14 13:31:47 EST 2024
STATUS

editing

proposed

Discussion
Wed Feb 14
13:32
M. F. Hasler: Yes, nice, please add the FORMULA!
13:37
M. F. Hasler: or maybe better : =A006254(n)
13:42
M. F. Hasler: ah no, sorry, =A006254(n)-2 ... not so nice. Also  A086801(n-1)/2 =  (prime(n-1)-3)/2.
#9 by M. F. Hasler at Wed Feb 14 11:00:37 EST 2024
COMMENTS

a(n) = 48 for all numbers of the form 32*p where p is prime, and for n = 171. (Is there any other?) This is by far the most frequent nonzero value, it can be seen as a horizontal line in the graph of the sequence.

a(n) = 11 for n = 5*709, 2*2833, 2*37*83, 2*29*107, 2*23*137, 2*17*191, 2*11*317, 2*7*569, 2*5*947, 2*3*2837, 2*3*53*67, ...: this This appears to be the second most frequent nonzero value. (End)

PROG

A356253(n) = {my(f = factor(n)); vecmax(Vec(prod(k=1, lengthvecprod(f~), [(x + f[k, 1])^f[k, 2] | f<-factor(n)~])))};

A003415(n) = if(n<=>1, 0, myvecsum([n/f[1]*f[2] | f=<-factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]), 0);

A369657(n) = (A356253(n)-A003415(n)); \\ This and above edited by _M. F. Hasler_, Feb 14 2024

STATUS

proposed

editing

Discussion
Wed Feb 14
13:31
Thomas Scheuerle: a(9*prime(n))/6 = A067076(n-1) n > 1