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 A020266 Strong pseudoprimes to base 40. 1
 39, 121, 289, 451, 703, 1561, 1921, 4961, 5729, 6601, 7111, 7201, 10897, 11041, 12403, 13333, 14023, 14701, 15211, 15793, 23521, 26797, 27133, 32657, 38081, 38503, 43213, 43621, 48133, 67721, 72433, 85879, 94249, 97393, 104977, 113201, 128143, 161701 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. J. Mathar, Table of n, a(n) for n = 1..300 MATHEMATICA strongPseudoprimeQ[b_, n_] := Module[{rems = Table[PowerMod[b, (n - 1)/2^expo, n], {expo, 0, IntegerExponent[n - 1, 2]}]}, (rems[[-1]] == 1 || MemberQ[rems, n - 1]) && PowerMod[b, n - 1, n] == 1]; max = 5000; Select[Complement[Range[2, max], Prime[Range[PrimePi[max]]]], strongPseudoprimeQ[40, #] &] (* Alonso del Arte, Aug 05 2018 *) CROSSREFS Sequence in context: A239562 A044290 A044671 * A033576 A082656 A072933 Adjacent sequences:  A020263 A020264 A020265 * A020267 A020268 A020269 KEYWORD nonn AUTHOR STATUS approved

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Last modified May 27 13:00 EDT 2020. Contains 334657 sequences. (Running on oeis4.)