A016747 a(n) = (2*n)^7.

0, 128, 16384, 279936, 2097152, 10000000, 35831808, 105413504, 268435456, 612220032, 1280000000, 2494357888, 4586471424, 8031810176, 13492928512, 21870000000, 34359738368, 52523350144, 78364164096, 114415582592, 163840000000, 230539333248, 319277809664, 435817657216

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..10000

Index entries for linear recurrences with constant coefficients, signature (8,-28,56,-70,56,-28,8,-1).

Formula

O.g.f.: 128*x*(1 + 120*x + 1191*x^2 + 2416*x^3 + 1191*x^4 + 120*x^5 + x^6)/(1-x)^8. - R. J. Mathar, May 07 2008

From Amiram Eldar, Oct 10 2020: (Start)

Sum_{n>=1} 1/a(n) = zeta(7)/128.

Sum_{n>=1} (-1)^(n+1)/a(n) = 63*zeta(7)/8192. (End)

Maple

A016747:=n->(2*n)^7: seq(A016747(n), n=0..40); # Wesley Ivan Hurt, Sep 15 2018

Mathematica

(2*Range[0, 20])^7  (* Harvey P. Dale, Jan 17 2011 *)

Prog

(Magma) [(2*n)^7: n in [0..30]]; // Vincenzo Librandi, Sep 05 2011
(PARI) vector(30, n, n--; (2*n)^7) \\ G. C. Greubel, Sep 15 2018

Crossrefs

Cf. A016759.

Sequence in context: A228985 A282315 A093532 * A189269 A223674 A189622

Adjacent sequences: A016744 A016745 A016746 * A016748 A016749 A016750

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved