A301721 Partial sums of A301720.

1, 7, 16, 34, 55, 79, 115, 151, 190, 244, 295, 349, 421, 487, 556, 646, 727, 811, 919, 1015, 1114, 1240, 1351, 1465, 1609, 1735, 1864, 2026, 2167, 2311, 2491, 2647, 2806, 3004, 3175, 3349, 3565, 3751, 3940, 4174, 4375, 4579, 4831, 5047, 5266, 5536, 5767, 6001, 6289, 6535, 6784, 7090, 7351, 7615, 7939, 8215, 8494, 8836

Offset: 0

Author

N. J. A. Sloane, Mar 26 2018

Keywords

• nonn

Comments

Linear recurrence and g.f. confirmed by Shutov/Maleev link in A301720. - Ray Chandler, Aug 30 2023

Links

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

Crossrefs

Cf. A301720.

Formula

From Colin Barker, Apr 09 2018: (Start)

G.f.: (1 + 6*x + 9*x^2 + 16*x^3 + 9*x^4 + 6*x^5 + x^6) / ((1 - x)^3*(1 + x + x^2)^2).

a(n) = a(n-1) + 2*a(n-3) - 2*a(n-4) - a(n-6) + a(n-7) for n>6.

(End)