OFFSET
1,1
PROG
(PARI) is(k) = sigma(k^3 + k + 1, -1) > 2; \\ Amiram Eldar, Apr 05 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Hans Havermann, Dec 21 2007
EXTENSIONS
a(21)-a(25) from Amiram Eldar, Apr 05 2024
STATUS
approved