A027745 Number of primitive polynomials of degree n over GF(9).

1, 4, 16, 96, 640, 5280, 27648, 340704, 1966080, 15676416, 124608000, 1341648000, 7166361600, 97763702400, 629315721216, 4680529920000, 42316647628800, 483414202656000, 2396062681399296, 35513562609100800, 211942058803200000, 2006922093666287616, 16837843397760000000

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..100

Crossrefs

Column k=9 of A369291.

Programs

Maple

with(numtheory): seq(`if`(n=0, 1, phi(9^n-1)/n), n=0..22);

Mathematica

Join[{1}, Array[EulerPhi[9^# - 1]/# &, 25]] (* Paolo Xausa, Jun 17 2024 *)

PARI

a(n) = if(n==0, 1, eulerphi(9^n-1)/n) \\ Andrew Howroyd, Feb 01 2024

Extensions

a(20) onwards from Andrew Howroyd, Feb 01 2024