A020217 Pseudoprimes to base 89.

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

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 * A370999 A329728 A141066

Adjacent sequences: A020214 A020215 A020216 * A020218 A020219 A020220

Keyword

nonn

Author

David W. Wilson

Status

approved