A298785 Partial sums of A298784.

1, 5, 11, 21, 35, 51, 71, 95, 121, 151, 185, 221, 261, 305, 351, 401, 455, 511, 571, 635, 701, 771, 845, 921, 1001, 1085, 1171, 1261, 1355, 1451, 1551, 1655, 1761, 1871, 1985, 2101, 2221, 2345, 2471, 2601, 2735, 2871, 3011, 3155, 3301, 3451, 3605, 3761, 3921, 4085, 4251, 4421, 4595, 4771

Offset

0,2

Links

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (2,-1,1,-2,1).

Formula

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

a(n) = 2*a(n-1) - a(n-2) + a(n-3) - 2*a(n-4) + a(n-5) for n>4. - Colin Barker, Jan 27 2018

Prog

(PARI) Vec((1 + x^2)*(1 + 3*x + x^2) / ((1 - x)^3*(1 + x + x^2)) + O(x^60)) \\ Colin Barker, Jan 27 2018

Crossrefs

Cf. A298784.

Sequence in context: A372906 A166480 A164096 * A163787 A166863 A163704

Adjacent sequences: A298782 A298783 A298784 * A298786 A298787 A298788

Keyword

nonn,easy

Author

N. J. A. Sloane, Jan 26 2018

Status

approved