A027695 Number of primitive polynomials of degree n over GF(4).

1, 2, 4, 12, 32, 120, 288, 1512, 4096, 15552, 48000, 240064, 552960, 3439800, 9483264, 35640000, 134217728, 673699800, 1451188224, 9644765256, 23685120000, 115605729792, 401556013056, 1996264531840, 4566087106560, 26244000000000, 89961392102400, 356237685227520

Offset

0,2

Links

Amiram Eldar, Table of n, a(n) for n = 0..1122 (terms 0..150 from Andrew Howroyd)

Formula

a(n) = A295501(n)/n = 2*A027742(n) for n >= 1. - Amiram Eldar, Nov 30 2024

Maple

with(numtheory): seq(`if`(n=0, 1, phi(4^n-1)/n), n=0..27);

Mathematica

Join[{1}, Array[EulerPhi[4^# - 1]/# &, 30]] (* Paolo Xausa, Jun 17 2024 *)

Prog

(PARI) a(n) = if(n==0, 1, eulerphi(4^n-1)/n) \\ Andrew Howroyd, Feb 01 2024

Crossrefs

Column k=4 of A369291.

Cf. A027742, A295501.

Sequence in context: A148194 A289501 A274961 * A148195 A169807 A005028

Adjacent sequences: A027692 A027693 A027694 * A027696 A027697 A027698

Keyword

nonn

Author

N. J. A. Sloane

Extensions

a(24) onwards from Andrew Howroyd, Feb 01 2024

Status

approved