A114946 Number of monic irreducible polynomials over GF(4) of degree <= n.

4, 10, 30, 90, 294, 964, 3304, 11464, 40584, 145338, 526638, 1924378, 7086598, 26259388, 97842104, 366273464, 1376854004, 5194587924, 19661846184, 74637375132, 284068160592, 1083712790142, 4143223406562, 15871346734402, 60907343008066, 234122710710436

Offset: 1

Author

Gary L Mullen (mullen(AT)math.psu.edu) and Ken Hicks, Jan 06 2006

Keywords

• nonn

Crossrefs

Partial sums of A027377. 4th column of A143328. - Alois P. Heinz, Sep 23 2008

Programs

Maple

with(numtheory):
b:= n-> add(mobius(d) *4^(n/d)/n, d=divisors(n)):
a:= n-> add(b(k), k=1..n):
seq(a(n), n=1..30); # Alois P. Heinz, Sep 23 2008

Mathematica

f[n_] := DivisorSum[n, MoebiusMu[#] * 4^(n/#) &] / n; Accumulate[Array[f, 26]] (* Amiram Eldar, Aug 24 2023 *)

PARI

a(n)=sum(m=1, n, 1/m* sumdiv(m, d, moebius(d)*4^(m/d) ) ); /* Joerg Arndt, Jul 04 2011 */

Extensions

More terms from Alois P. Heinz, Sep 23 2008