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Numbers b such that b is not a power of 2 and both 1093 and 3511 are base-b Wieferich primes.
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%I #14 Mar 16 2016 16:47:23

%S 429327,858654,1717308,3434616,6869232,13738464,14583415,27476928,

%T 29166830,31995179,46455089,54953856,57420033,58333660,58473815,

%U 60227705,63990358,66863995,71828271,72766215,84301671,86290359,91406901,92910178,94508343,97720353

%N Numbers b such that b is not a power of 2 and both 1093 and 3511 are base-b Wieferich primes.

%C Intersection of A057716 and A247208.

%C All terms of A247214, except 2, appear in the sequence.

%e The sequence w of primes p such that 429327^(p-1) == 1 (mod p^2) starts 1093, 3511, 2652379, 20793169. Since both 1093 and 3511 are terms of w, 429327 is in this sequence.

%o (PARI) my(p=1093, q=3511); for(n=2, 1e9, if(Mod(n, p^2)^(p-1)==1 && Mod(n, q^2)^(q-1)==1, my(x=2); while(x < n, x=2*x); if(x!=n, print1(n, ", "))))

%Y Cf. A057716, A247208, A247214.

%K nonn

%O 1,1

%A _Felix Fröhlich_, Mar 05 2016