A054605 a(n) = Sum_{d|6} phi(d)*n^(6/d).

0, 6, 84, 780, 4200, 15810, 46956, 118104, 262800, 532350, 1001220, 1773156, 2988024, 4829370, 7532700, 11394480, 16781856, 24143094, 34018740, 47053500, 64008840, 85776306, 113391564, 148049160, 191118000, 244157550, 308934756

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 (7,-21,35,-35,21,-7,1).

Crossrefs

Row n=6 of A185651.

Programs

Mathematica

Table[n^6+n^3+2n^2+2n,{n,0,30}] (* or *) LinearRecurrence[{7,-21,35,-35,21,-7,1},{0,6,84,780,4200,15810,46956},30] (* Harvey P. Dale, Mar 11 2023 *)

Formula

a(n) = n^6 + n^3 + 2n^2 + 2n. - Ralf Stephan, Sep 03 2003

G.f.: -6*x*(10*x^4+49*x^3+53*x^2+7*x+1) / (x-1)^7. - Colin Barker, Dec 21 2012