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%I #15 Oct 05 2015 12:39:59
%S 4,8,16,32,85,496,545,703,1057,1105,1417,1649,1729,1853,2465,2501,
%T 2821,3368,4033,4492,4681,5461,5713,5833,6533,6601,7861,8911,9061,
%U 9073,9265,10585,11305,11359,12209,12403,13741,15841,16589,16745,17968,18103,19909
%N Pseudoprimes to base 33.
%C Composite numbers n such that 33^(n-1) == 1 (mod n).
%H T. D. Noe, <a href="/A020161/b020161.txt">Table of n, a(n) for n = 1..1000</a>
%H <a href="/index/Ps#pseudoprimes">Index entries for sequences related to pseudoprimes</a>
%t base = 33; 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 *)
%t Select[Range[20000],CompositeQ[#]&&PowerMod[33,#-1,#]==1&] (* _Harvey P. Dale_, Oct 05 2015 *)
%Y Cf. A001567 (pseudoprimes to base 2).
%K nonn
%O 1,1
%A _David W. Wilson_