A020218 Pseudoprimes to base 90.

91, 623, 703, 793, 1001, 1157, 1729, 2047, 2413, 2821, 3091, 3367, 4033, 4699, 6281, 6601, 8099, 8321, 8401, 8911, 11521, 11557, 12403, 13021, 13333, 13981, 14701, 14981, 15841, 17701, 19307, 19951, 20017, 20263, 24641, 24661, 25571, 29341, 31021

Offset

1,1

Comments

Composite numbers n such that 90^(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 = 90; 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: A211447 A188360 A165220 * A217841 A338795 A084319

Adjacent sequences: A020215 A020216 A020217 * A020219 A020220 A020221

Keyword

nonn

Author

David W. Wilson

Status

approved