A016840 a(n) = (4*n+3)^4.

81, 2401, 14641, 50625, 130321, 279841, 531441, 923521, 1500625, 2313441, 3418801, 4879681, 6765201, 9150625, 12117361, 15752961, 20151121, 25411681, 31640625, 38950081, 47458321, 57289761

Offset

0,1

Links

Table of n, a(n) for n=0..21.

Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

Formula

a(n) = 5*a(n-1)- 10*a(n-2)+10*a(n-3)-5*a(n-4)+a(n-5). - Harvey P. Dale, Dec 08 2011

Sum_{n>=0} 1/a(n) = A390075 / (6*4^4). - R. J. Mathar, Oct 24 2025

Mathematica

(4*Range[0, 30]+3)^4 (* or *) LinearRecurrence[{5, -10, 10, -5, 1}, {81, 2401, 14641, 50625, 130321}, 30] (* Harvey P. Dale, Dec 08 2011 *)

Crossrefs

Sequence in context: A233023 A236989 A038676 * A128832 A085877 A123219

Adjacent sequences: A016837 A016838 A016839 * A016841 A016842 A016843

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved