OFFSET
1,1
COMMENTS
Odd composite integer n is in this sequence if n == 1 or p (mod (p^2-1)/2) for every prime p|n.
No other terms below 10^22.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Max Alekseyev, Feb 19 2018
EXTENSIONS
a(9) from Daniel Suteu confirmed and a(10) added by Max Alekseyev, Dec 16 2020
a(11)-a(12) from Max Alekseyev, Apr 21 2024
STATUS
approved