OFFSET
1,1
COMMENTS
a(17) > 3*10^9. - Jinyuan Wang, Jul 09 2019
a(24) > 10^12, if it exists. - Giovanni Resta, Jul 17 2019
EXAMPLE
6^2 + tau(6)^2 + sigma(6)^2 = 36 + 16 + 144 = 196 = 14^2. So 6 is in the sequence.
PROG
(PARI) isok(n) = issquare(n^2 + numdiv(n)^2 + sigma(n)^2);
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Michel Marcus, Jun 05 2014
EXTENSIONS
a(13)-a(16) from Jinyuan Wang, Jul 09 2019
a(17)-a(23) from Giovanni Resta, Jul 17 2019
STATUS
approved