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A020217 Pseudoprimes to base 89. 1
4, 8, 9, 15, 22, 33, 44, 45, 55, 85, 88, 99, 153, 165, 169, 341, 385, 495, 561, 765, 1035, 1045, 1105, 1165, 1309, 1387, 1441, 1541, 1581, 1649, 1729, 2097, 2465, 2529, 2611, 2701, 2805, 2821, 2977, 3015, 3201, 3961, 4015, 4061, 4187, 4371, 4777, 4849, 5005 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Composite numbers n such that 89^(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 = 89; 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 *)

Select[Range[5500], CompositeQ[#]&&PowerMod[89, #-1, #]==1&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 06 2018 *)

CROSSREFS

Cf. A001567 (pseudoprimes to base 2).

Sequence in context: A158337 A161542 A131195 * A141066 A018196 A072103

Adjacent sequences:  A020214 A020215 A020216 * A020218 A020219 A020220

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified June 25 11:59 EDT 2019. Contains 324352 sequences. (Running on oeis4.)