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A373277
Number of monic irreducible polynomials over GF(7) with fixed nonzero trace.
2
1, 3, 16, 84, 480, 2792, 16807, 102900, 640528, 4035120, 25679568, 164775800, 1064714400, 6920635197, 45214871360, 296722542900, 1954878268800, 12923917122536, 85705978837392, 569944757250960, 3799631728452112, 25388448354582216, 169992219503608176
OFFSET
1,2
FORMULA
a(n) = 1/(7*n) * Sum_{d|n, gcd(d,7)=1} mu(d) * 7^(n/d).
PROG
(PARI) a(n) = sumdiv(n, d, (gcd(d, 7)==1)*(moebius(d)*7^(n/d)))/(7*n);
CROSSREFS
Column 7 of A110540.
Sequence in context: A026131 A026160 A025187 * A151328 A277923 A076279
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 29 2024
STATUS
approved