A020219 Pseudoprimes to base 91.

6, 9, 10, 15, 18, 30, 45, 66, 69, 90, 115, 205, 207, 341, 345, 369, 435, 505, 561, 909, 1035, 1065, 1387, 1446, 1541, 1845, 2047, 2059, 2465, 2651, 2701, 2829, 2871, 3015, 4005, 4141, 4187, 4371, 4545, 5963, 6273, 6533, 6969, 7471, 8646, 9361, 9881, 10585

Offset

1,1

Comments

Composite numbers n such that 91^(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 = 91; 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[11000], CompositeQ[#]&&PowerMod[91, #-1, #]==1&] (* Harvey P. Dale, Aug 15 2017 *)

Crossrefs

Cf. A001567 (pseudoprimes to base 2).

Sequence in context: A054020 A121014 A153519 * A175634 A134622 A130593

Adjacent sequences: A020216 A020217 A020218 * A020220 A020221 A020222

Keyword

nonn

Author

David W. Wilson

Status

approved