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Pseudoprimes to base 71.
1

%I #13 Aug 03 2014 14:01:12

%S 9,10,14,15,21,35,45,63,70,105,231,315,370,435,561,703,1035,1105,1387,

%T 1729,1921,2071,2209,2321,2465,2701,2821,2871,3290,4005,4033,4431,

%U 5565,6541,6601,7345,7957,8295,8365,8695,8911,9637,9730,9809,10349,10585

%N Pseudoprimes to base 71.

%C Composite numbers n such that 71^(n-1) == 1 (mod n).

%H T. D. Noe, <a href="/A020199/b020199.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 = 71; 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_