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A153514 Terms of A122780 which are not Carmichael numbers A002997.

%I A153514 #12 Mar 27 2019 09:53:07
%S A153514 1,6,66,91,121,286,671,703,726,949,1541,1891,2665,2701,3281,3367,3751,
%T A153514 4961,5551,7107,7381,8205,8401,8646,11011,12403,14383,15203,15457,
%U A153514 16471,16531,18721,19345,23521,24046,24661,24727,28009,29161,30857,31621
%N A153514 Terms of A122780 which are not Carmichael numbers A002997.
%C A153514 For the intersection of this sequence and A153508, see A153513.
%H A153514 Robert Israel, <a href="/A153514/b153514.txt">Table of n, a(n) for n = 1..1000</a>
%p A153514 filter:= proc(n) local p;
%p A153514   if isprime(n) or (3 &^n - 3 mod n <> 0) then return false fi;
%p A153514   if n::even then return true fi;
%p A153514   if not numtheory:-issqrfree(n) then return true fi;
%p A153514   for p in numtheory:-factorset(n) do
%p A153514     if n-1 mod (p-1) <> 0 then return true fi
%p A153514   od;
%p A153514 false
%p A153514 end proc:
%p A153514 filter(1):= true:
%p A153514 select(filter, [$1..10^5]); # _Robert Israel_, Jan 29 2017
%t A153514 okQ[n_] := !PrimeQ[n] && PowerMod[3, n, n] == Mod[3, n] && Mod[n, CarmichaelLambda[n]] != 1;
%t A153514 Select[Range[10^5], okQ] (* _Jean-François Alcover_, Mar 27 2019 *)
%Y A153514 Cf. A002997, A122780, A153508, A153513.
%K A153514 nonn
%O A153514 1,2
%A A153514 _Artur Jasinski_, Dec 28 2008