OFFSET
1,3
COMMENTS
From M. F. Hasler, Feb 14 2024: (Start)
a(n) = 0 for most n divisible by 4, except 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. (Are there any others?) 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 appears to be the second most frequent nonzero value. (End)
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..30030
FORMULA
a(9*prime(n)) = 3*A086801(n) for n > 1. - Thomas Scheuerle, Feb 14 2024
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Feb 08 2024
STATUS
approved