A028358 Partial sums of A028357.

1, 4, 10, 20, 33, 48, 64, 82, 103, 128, 156, 186, 217, 250, 286, 326, 369, 414, 460, 508, 559, 614, 672, 732, 793, 856, 922, 992, 1065, 1140, 1216, 1294, 1375, 1460, 1548, 1638, 1729, 1822, 1918, 2018, 2121

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (3,-3,0,3,-3,1).

Programs

Mathematica

LinearRecurrence[{3,-3,0,3,-3,1},{1,4,10,20,33,48},50] (* Harvey P. Dale, Jun 14 2021 *)
Table[(9 + 72n + 30n^2 + 32Cos[(n + 1)Pi/3] - (-1)^n)/24, {n, 0, 40}] (* Greg Dresden, Jun 22 2021 *)

Formula

G.f.: ( -1-x-x^2-2*x^3 ) / ( (1+x)*(x^2-x+1)*(x-1)^3 ). - R. J. Mathar, Dec 15 2015

a(n) = (9 + 72*n + 30*n^2 + 32*cos((n + 1)*Pi/3) - (-1)^n)/24. - Greg Dresden, Jun 22 2021