A020178 Pseudoprimes to base 50.

21, 49, 51, 119, 133, 147, 231, 301, 357, 561, 637, 697, 793, 817, 833, 861, 931, 1037, 1281, 1649, 1729, 2009, 2041, 2047, 2107, 2499, 2501, 2701, 2821, 2989, 3201, 3281, 3913, 3977, 4753, 5461, 5719, 6601, 7693, 7701, 8041, 8113, 8911, 9061, 9073, 9331

Offset

1,1

Comments

Composite numbers n such that 50^(n-1) == 1 (mod n). - Michel Lagneau, Feb 18 2012

Links

T. D. Noe, Table of n, a(n) for n = 1..1000

Index entries for sequences related to pseudoprimes

Mathematica

base = 50; 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 *)

Crossrefs

Cf. A001567 (pseudoprimes to base 2).

Sequence in context: A146713 A140681 A262423 * A347372 A141556 A147281

Adjacent sequences: A020175 A020176 A020177 * A020179 A020180 A020181

Keyword

nonn

Author

David W. Wilson

Status

approved