A016863 a(n) = (5*n + 1)^3.

1, 216, 1331, 4096, 9261, 17576, 29791, 46656, 68921, 97336, 132651, 175616, 226981, 287496, 357911, 438976, 531441, 636056, 753571, 884736, 1030301, 1191016, 1367631, 1560896, 1771561, 2000376, 2248091, 2515456, 2803221, 3112136, 3442951, 3796416, 4173281, 4574296

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Examples

			a(0) = (5*0 + 1)^3 = 1.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 0..10000
• Eric Weisstein's MathWorld, Polygamma Function.
• Wikipedia, Polygamma Function.
• Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Crossrefs

Cf. A000578, A016861, A016862, A016864.

Programs

Mathematica

Table[(5*n + 1)^3, {n, 0, 25}] (* Amiram Eldar, Oct 02 2020 *)

Formula

Sum_{n>=0} 1/a(n) = -polygamma(2, 1/5)/250. - Amiram Eldar, Oct 02 2020

From Wesley Ivan Hurt, Oct 02 2020: (Start)

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).

G.f.: (1+212*x+473*x^2+64*x^3)/(-1+x)^4. (End)

From Stefano Spezia, Nov 01 2024: (Start)

a(n) = A000578(A016861(n)).

E.g.f.: exp(x)*(1 + 215*x + 450*x^2 + 125*x^3). (End)