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A020151 Pseudoprimes to base 23. 2

%I #14 Aug 03 2014 14:01:10

%S 22,33,91,154,165,169,265,341,385,451,481,553,561,638,946,1027,1045,

%T 1065,1105,1183,1271,1729,1738,1749,2059,2321,2465,2501,2701,2821,

%U 2926,3097,3445,4033,4081,4345,4371,4681,5005,5149,6253,6369,6533,6541,7189,7267

%N Pseudoprimes to base 23.

%C Composite numbers n such that 23^(n-1) == 1 (mod n).

%H R. J. Mathar, <a href="/A020151/b020151.txt">Table of n, a(n) for n=1..1085</a>

%H <a href="/index/Ps#pseudoprimes">Index entries for sequences related to pseudoprimes</a>

%t base = 23; t = {}; n = 1; While[Length[t] < 100, n++; If[! PrimeQ[n] && PowerMod[base, n-1, n] == 1, AppendTo[t, n]]]; t (* _T. D. Noe_, Feb 21 2012 *)

%Y Cf. A001567 (pseudoprimes to base 2).

%K nonn

%O 1,1

%A _David W. Wilson_

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Last modified April 20 16:37 EDT 2024. Contains 371845 sequences. (Running on oeis4.)