%I
%S 443372888629441,582920080863121,39671149333495681,842526563598720001,
%T 2380296518909971201,3188618003602886401,33711266676317630401,
%U 54764632857801026161,122762671289519184001,361266866679292635601
%N Carmichael numbers (A002997) that are Chebyshev pseudoprimes (A175530).
%C Odd composite integer n is in this sequence if n == 1 or p (mod (p^21)/2) for every prime pn.
%C No other terms below 10^21.
%Y Intersection of A002997 and A175530.
%Y Contains A175531 as a subsequence.
%K nonn,hard,more
%O 1,1
%A _Max Alekseyev_, Feb 19 2018
%E a(9) from _Daniel Suteu_ confirmed and a(10) added by _Max Alekseyev_, Dec 16 2020
