A020170 - OEIS

A020170

Pseudoprimes to base 42.

205, 451, 529, 559, 697, 1105, 1247, 1441, 1541, 1763, 1765, 1807, 1891, 1921, 1991, 2465, 2665, 5371, 5611, 5977, 6001, 7345, 7421, 8041, 8749, 9773, 10585, 10621, 11041, 12167, 12403, 13333, 13981, 14473, 14491, 14981, 15457, 17611, 18721, 22399

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OFFSET

1,1

COMMENTS

Composite numbers n such that 42^(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 = 42; 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: A191834 A042983 A186475 * A260471 A249703 A015974

Adjacent sequences: A020167 A020168 A020169 * A020171 A020172 A020173

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved