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A114947 Number of monic irreducible polynomials over GF(5) of degree <= n. 2
5, 15, 55, 205, 829, 3409, 14569, 63319, 280319, 1256567, 5695487, 26039187, 119939427, 555899247, 2590404239, 12127122989, 57005914349, 268933430849, 1272801132329, 6041172226049, 28747703565329, 137119782755669, 655421041672109, 3138947897124609 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..1000

FORMULA

a(n) ~ 5^(n+1) / (4*n). - Vaclav Kotesovec, Sep 05 2014

MAPLE

with(numtheory):

b:= n-> add(mobius(d) *5^(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

PROG

(PARI) a(n)=sum(m=1, n, 1/m* sumdiv(m, d, moebius(d)*5^(m/d) ) ); /* Joerg Arndt, Jul 04 2011 */

CROSSREFS

Partial sums of A001692. 5th column of A143328. - Alois P. Heinz, Sep 23 2008

Sequence in context: A006358 A054108 A149585 * A316104 A149586 A149587

Adjacent sequences:  A114944 A114945 A114946 * A114948 A114949 A114950

KEYWORD

nonn

AUTHOR

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

EXTENSIONS

More terms from Alois P. Heinz, Sep 23 2008

STATUS

approved

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Last modified December 12 17:33 EST 2019. Contains 329960 sequences. (Running on oeis4.)