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Pseudoprimes to base 99.
2

%I #18 Jul 16 2015 12:09:20

%S 14,25,35,49,65,98,145,169,175,217,245,325,361,377,637,703,725,742,

%T 775,833,845,1105,1225,1421,1519,1729,1834,1885,2191,2198,2413,2465,

%U 2821,3185,3277,3565,4069,4123,4225,4699,4753,4795,4901,5365,5425,5611,6601

%N Pseudoprimes to base 99.

%C Composite numbers n such that 99^(n-1) == 1 (mod n).

%H T. D. Noe, <a href="/A020227/b020227.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 = 99; 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[7000],CompositeQ[#]&&PowerMod[99,#-1,#]==1&] (* _Harvey P. Dale_, Jul 16 2015 *)

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

%K nonn

%O 1,1

%A _David W. Wilson_