A020196 Pseudoprimes to base 68.

25, 49, 69, 91, 125, 133, 185, 201, 217, 247, 325, 345, 361, 403, 469, 481, 589, 637, 805, 871, 925, 931, 1005, 1025, 1221, 1225, 1273, 1417, 1519, 1541, 1725, 1729, 1771, 1813, 2077, 2185, 2211, 2413, 2527, 2553, 2665, 2725, 2821, 3283, 3325, 3565, 4033, 4123

Offset

1,1

Comments

Composite numbers n such that 68^(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

max = 5000; Select[Complement[Range[max], Prime[Range[PrimePi[max]]]], PowerMod[68, # - 1, #] == 1 &] (* Alonso del Arte, Jun 17 2018 *)

Crossrefs

Cf. A001567 (pseudoprimes to base 2).

Sequence in context: A322121 A020146 A020244 * A020294 A103214 A067778

Adjacent sequences: A020193 A020194 A020195 * A020197 A020198 A020199

Keyword

nonn

Author

David W. Wilson

Status

approved