A036683 T(n+4,4) with T as in A036355.

5, 20, 71, 207, 556, 1390, 3310, 7576, 16807, 36331, 76850, 159575, 326092, 657124, 1307992, 2575180, 5020570, 9702043, 18599391, 35397328, 66918850, 125738650, 234930380, 436660010, 807690455, 1487269940, 2727149885, 4981046893

Offset: 0

Author

Floor van Lamoen

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (5,-5,-10,15,11,-15,-10,5,5,1).

Programs

Mathematica

LinearRecurrence[{5,-5,-10,15,11,-15,-10,5,5,1},{5,20,71,207,556,1390,3310,7576,16807,36331},30] (* Harvey P. Dale, May 26 2025 *)

Formula

G.f.: (x^4+2x^3-4x^2-5x+5)/(1-x-x^2)^5.

a(n) = A001628(n)+3*A001872(n)+A001873(n). - R. J. Mathar, Jul 03 2022