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%I #16 Dec 06 2020 00:05:45
%S 2,3,4,6,11,12,14,15,16,20,34,36,39,47,52,56,58,59,66,72,83,84,86,87,
%T 88,90,92,95,96,102,103,104,106,108,111,114,119,123,135,139,140,142,
%U 144,156,159,160,162,167,171,175,180,183,186,187,194,198,200,203,204
%N Bases b for which no primes p with p < b exist such that p is a base-b Wieferich prime.
%C Numbers b such that A255920(b) = 0.
%C Complement of A273786. - _Felix Fröhlich_, Dec 03 2020
%H Felix Fröhlich, <a href="/A255921/b255921.txt">Table of n, a(n) for n = 1..10000</a>
%o (PARI) is(b) = forprime(p=1, b-1, if(Mod(b, p^2)^(p-1)==1, return(0))); 1
%Y Cf. A255920, A255922, A255923, A255924, A255925, A273786.
%K nonn
%O 1,1
%A _Felix Fröhlich_, Mar 11 2015