A130438 - OEIS

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A130438

Even pseudoprimes to base 23.

22, 154, 638, 946, 1738, 2926, 12166, 15862, 33022, 125686, 248218, 285286, 358534, 596926, 697334, 1007566, 3426346, 3675826, 3755158, 4147522, 6518974, 19866946, 26336926, 34220746, 35083426, 46365814, 54148654, 54342046, 72789466

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..153 (terms below 10^11; terms 1..78 from Robert G. Wilson v)

Eric Weisstein's World of Mathematics, Fermat Pseudoprime.

Index entries for sequences related to pseudoprimes.

MATHEMATICA

lst = {}; Do[ If[ PowerMod[17, 2n - 1, 2n] == 1, AppendTo[lst, 2n]], {n, 2, 2*10^9}]; lst (* Robert G. Wilson v, Jun 01 2007 *)

PROG

(PARI) is(k) = k > 2 && !(k % 2) && Mod(23, k)^(k-1) == 1; \\ Amiram Eldar, Sep 29 2024

CROSSREFS