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A020189 Pseudoprimes to base 61. 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 16 14:56 EDT 2019. Contains 324152 sequences. (Running on oeis4.)