A337282 Partial sums of A337281.

0, 0, 2, 5, 13, 33, 75, 166, 358, 754, 1564, 3203, 6491, 13043, 26021, 51596, 101772, 199828, 390790, 761537, 1479337, 2865589, 5536719, 10673010, 20530866, 39417766, 75545728, 144551167, 276172727, 526908583, 1003986313, 1910718488, 3632257048, 6897610216, 13085528650, 24801630845, 46966595909, 88866759433

Offset: 0

Author

N. J. A. Sloane, Sep 12 2020

Keywords

• nonn

References

• R. Schumacher, Explicit formulas for sums involving the squares of the first n Tribonacci numbers, Fib. Q., 58:3 (2020), 194-202.

Links

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

Crossrefs

Cf. A000073, A337281.

Formula

From Colin Barker, Sep 13 2020: (Start)

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

a(n) = 3*a(n-1) - a(n-2) - a(n-3) - 3*a(n-4) + a(n-5) + a(n-6) + a(n-7) for n>6.

(End)