A017116 a(n) = (8*n + 4)^4.

256, 20736, 160000, 614656, 1679616, 3748096, 7311616, 12960000, 21381376, 33362176, 49787136, 71639296, 100000000, 136048896, 181063936, 236421376, 303595776, 384160000, 479785216, 592240896, 723394816, 875213056, 1049760000, 1249198336, 1475789056, 1731891456

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..10000
• Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

Crossrefs

Cf. A016756, A016828, A017113.

Programs

Magma

[(8*n+4)^4: n in [0..35] ]; // Vincenzo Librandi, Jul 21 2011

Mathematica

(8*Range[0,20]+4)^4 (* or *) LinearRecurrence[{5,-10,10,-5,1},{256,20736,160000,614656,1679616},20] (* Harvey P. Dale, Aug 05 2019 *)

Formula

G.f.: -256*(1 + 76*x + 230*x^2 + 76*x^3 + x^4)/(x-1)^5. - R. J. Mathar, May 08 2015

From Amiram Eldar, Apr 25 2023: (Start)

a(n) = A017113(n)^4.

a(n) = 2^4*A016828(n) = 2^8*A016756(n).

Sum_{n>=0} 1/a(n) = Pi^4/24576. (End)