A016924 a(n) = (6*n + 1)^4.

1, 2401, 28561, 130321, 390625, 923521, 1874161, 3418801, 5764801, 9150625, 13845841, 20151121, 28398241, 38950081, 52200625, 68574961, 88529281, 112550881, 141158161, 174900625, 214358881, 260144641, 312900721, 373301041, 442050625, 519885601, 607573201, 705911761

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..2000
• Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

Crossrefs

Cf. A016921, A016922, A016923, A016925, A016926.

Programs

Magma

[(6*n+1)^4: n in [0..50]]; // Vincenzo Librandi, May 04 2011

Mathematica

(6Range[0,30]+1)^4 (* Harvey P. Dale, May 18 2011 *)

Formula

From Amiram Eldar, Mar 28 2022: (Start)

a(n) = A016921(n)^4 = A016922(n)^2.

Sum_{n>=0} 1/a(n) = PolyGamma(3, 1/6)/7776. (End)