A020189 Pseudoprimes to base 61.

4, 6, 10, 12, 15, 20, 30, 52, 60, 91, 93, 130, 155, 190, 217, 341, 388, 403, 465, 561, 679, 786, 970, 1105, 1261, 1441, 1729, 2388, 2465, 2701, 2821, 3007, 3406, 3565, 3661, 4061, 4123, 4371, 4577, 4580, 5044, 5356, 5461, 6541, 6601, 6697, 6799, 7107, 7372

Offset

1,1

Comments

Composite numbers n such that 61^(n-1) == 1 (mod n).

Links

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

Index entries for sequences related to pseudoprimes

Mathematica

base = 61; 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: A066190 A058012 A026411 * A166986 A318487 A047233

Adjacent sequences: A020186 A020187 A020188 * A020190 A020191 A020192

Keyword

nonn

Author

David W. Wilson

Status

approved