OFFSET
1,2
COMMENTS
LINKS
Jianing Song, Table of n, a(n) for n = 1..11086 (all terms <= 20000)
EXAMPLE
20 is a term since 20 and sigma(2*20^2) = 1953 are coprime.
PROG
(PARI) isA356449(n) = gcd(n, sigma(2*n^2))==1
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jianing Song, Aug 07 2022
STATUS
approved