A094919 a(n) = (4^n-1)/3 mod n.

0, 1, 0, 1, 1, 3, 1, 5, 0, 5, 1, 9, 1, 5, 6, 5, 1, 9, 1, 5, 0, 5, 1, 21, 16, 5, 0, 1, 1, 15, 1, 21, 21, 5, 26, 9, 1, 5, 21, 5, 1, 21, 1, 41, 36, 5, 1, 21, 22, 25, 21, 33, 1, 27, 11, 5, 21, 5, 1, 45, 1, 5, 0, 21, 16, 45, 1, 17, 21, 15, 1, 45, 1, 5, 66, 9, 5, 39, 1, 5, 0, 5, 1, 21, 1, 5, 21, 21, 1, 45

Offset: 1

Author

N. J. A. Sloane, Jun 18 2004

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..20000

Crossrefs

Cf. also A094922.

Programs

Mathematica

Table[Mod[(4^n-1)/3,n],{n,100}] (* Harvey P. Dale, Apr 11 2013 *)

PARI

A094919(n) = ((((4^n)-1)/3)%n); \\ Antti Karttunen, Feb 18 2023