A020140 Pseudoprimes to base 12.

65, 91, 133, 143, 145, 247, 377, 385, 703, 1045, 1099, 1105, 1649, 1729, 1885, 1891, 2041, 2233, 2465, 2701, 2821, 2983, 3367, 3553, 5005, 5365, 5551, 5785, 6061, 6305, 6601, 8911, 9073, 10585, 11077, 12403, 12673, 12905, 13051, 13333, 13345, 13585

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Composite numbers n such that 12^(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

Crossrefs

Cf. A001567 (pseudoprimes to base 2).

Programs

Mathematica

base = 12; 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 *)