%I #13 Aug 03 2014 14:01:12
%S 74,91,133,247,259,289,427,481,703,793,1073,1159,1261,1387,1541,1649,
%T 1729,1849,1891,2071,2257,2413,2701,2813,2821,3367,3589,4033,4681,
%U 4699,4921,5551,5917,6061,6533,6601,6643,7957,8113,8321,8614,8911,9139,9211
%N Pseudoprimes to base 75.
%C Composite numbers n such that 75^(n-1) == 1 (mod n).
%H T. D. Noe, <a href="/A020203/b020203.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 = 75; 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_