%I #15 Apr 06 2018 12:57:16
%S 4,8,9,15,22,33,44,45,55,85,88,99,153,165,169,341,385,495,561,765,
%T 1035,1045,1105,1165,1309,1387,1441,1541,1581,1649,1729,2097,2465,
%U 2529,2611,2701,2805,2821,2977,3015,3201,3961,4015,4061,4187,4371,4777,4849,5005
%N Pseudoprimes to base 89.
%C Composite numbers n such that 89^(n-1) == 1 (mod n).
%H T. D. Noe, <a href="/A020217/b020217.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 = 89; 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[5500],CompositeQ[#]&&PowerMod[89,#-1,#]==1&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Apr 06 2018 *)
%Y Cf. A001567 (pseudoprimes to base 2).
%K nonn
%O 1,1
%A _David W. Wilson_