A054607 a(n) = Sum_{d|8} phi(d)*n^(8/d).

0, 8, 288, 6672, 65840, 391320, 1681008, 5767328, 16781472, 43053480, 100010240, 214373808, 430002768, 815759672, 1475827920, 2562941760, 4295033408, 6975841608, 11020066272, 16983694160, 25600160880, 37823054808, 54876108848

Offset: 0

Author

N. J. A. Sloane, Apr 16 2000

Keywords

• nonn
• easy

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..10000
• Index entries for linear recurrences with constant coefficients, signature (9,-36,84,-126,126,-84,36,-9,1).

Crossrefs

Row n=8 of A185651.

Programs

PARI

a(n) = n^8+n^4+2*n^2+4*n; \\ Seiichi Manyama, Jul 11 2021

Formula

G.f.: -8*x*(34*x^6+525*x^5+1971*x^4+1936*x^3+546*x^2+27*x+1) / (x-1)^9. [Colin Barker, Dec 21 2012]

a(n) = n^8 + n^4 + 2*n^2 + 4*n. - Seiichi Manyama, Jul 11 2021