A211457 - OEIS

A211457

Largest number b for which A181780(n) is a Fermat pseudoprime.

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

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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