A365418 Partial sums of A301298.

1, 6, 15, 29, 48, 71, 99, 132, 169, 211, 258, 309, 365, 426, 491, 561, 636, 715, 799, 888, 981, 1079, 1182, 1289, 1401, 1518, 1639, 1765, 1896, 2031, 2171, 2316, 2465, 2619, 2778, 2941, 3109, 3282, 3459, 3641, 3828, 4019, 4215, 4416, 4621, 4831, 5046, 5265, 5489, 5718, 5951, 6189, 6432, 6679, 6931, 7188, 7449

Offset: 0

Author

Ray Chandler, Sep 03 2023

Keywords

• nonn
• easy

Links

• Ray Chandler, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (2,-1,1,-2,1).

Crossrefs

Cf. A301298.

Programs

Mathematica

LinearRecurrence[{2, -1, 1, -2, 1}, {1, 6, 15, 29, 48}, 50]

Formula

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

a(n) = 2*a(n-1) - a(n-2) + a(n-3) - 2*a(n-4) + a(n-5) for n > 5.