A020206 Pseudoprimes to base 78.

77, 341, 385, 451, 553, 703, 869, 1045, 1247, 1271, 1441, 1849, 1921, 2047, 2465, 2765, 3097, 4061, 4187, 4345, 4577, 5371, 6031, 6083, 6085, 6545, 6601, 8321, 8911, 8965, 10585, 13333, 13981, 15211, 15251, 15841, 17711, 17767, 20689, 22801, 23281, 23617

Offset

1,1

Comments

Composite numbers n such that 78^(n-1) == 1 (mod n). - Michel Lagneau, Feb 18 2012

Links

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

Index entries for sequences related to pseudoprimes

Mathematica

base = 78; 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[25000], CompositeQ[#]&&PowerMod[78, #-1, #]==1&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Oct 11 2019 *)

Crossrefs

Cf. A001567 (pseudoprimes to base 2).

Sequence in context: A158767 A158771 A331976 * A020304 A154058 A027574

Adjacent sequences: A020203 A020204 A020205 * A020207 A020208 A020209

Keyword

nonn

Author

David W. Wilson

Status

approved