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 A211457 Largest number b for which A181780(n) is a Fermat pseudoprime. 6
 11, 13, 18, 25, 23, 29, 25, 37, 31, 35, 29, 34, 37, 55, 57, 49, 47, 51, 49, 49, 43, 81, 59, 88, 61, 56, 89, 97, 73, 81, 91, 109, 69, 118, 83, 25, 68, 85, 81, 125, 109, 95, 131, 133, 97, 137, 145, 67, 94, 107, 139, 142, 150, 134, 165, 151, 113, 119, 121, 179 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS That is, the largest b for which b^(s-1) = 1 (mod s), where s is in A181780. LINKS T. D. Noe, Table of n, a(n) for n = 1..10000 MATHEMATICA t = {}; n = 1; While[Length[t] < 100, n++; If[! PrimeQ[n], s = Select[Range[2, n-2], PowerMod[#, n-1, n] == 1 &]; If[s != {}, AppendTo[t, {n, Length[s], s}]]]]; Last/@Transpose[t][[3]] CROSSREFS Cf. A181780, A211455, A211456, A211458. Sequence in context: A098423 A178339 A088561 * A154523 A107932 A143365 Adjacent sequences:  A211454 A211455 A211456 * A211458 A211459 A211460 KEYWORD nonn AUTHOR T. D. Noe, Apr 13 2012 STATUS approved

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Last modified December 10 00:54 EST 2019. Contains 329885 sequences. (Running on oeis4.)