OFFSET
1,1
COMMENTS
LINKS
Jianing Song, Table of n, a(n) for n = 1..11669 (all terms <= 100000)
EXAMPLE
28 is a term since 28 and sigma(2*28^2) = 3591 have a common factor 7, and 28 is not divisible by 3.
PROG
(PARI) isA356456(n) = (n%3) && gcd(n, sigma(2*n^2))>1
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jianing Song, Aug 07 2022
STATUS
approved