A131405 Row sums of triangle A131404.

1, 2, 7, 16, 37, 82, 179, 384, 813, 1702, 3531, 7272, 14889, 30342, 61603, 124700, 251825, 507582, 1021535, 2053388, 4123481, 8274002, 16591767, 33254356, 66623317, 133432082, 267164239, 534814024, 1070413693, 2142098602, 4286254091, 8575836312, 17157057669

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..500

Index entries for linear recurrences with constant coefficients, signature (5, -8, 3, 3, -2)

Formula

From Andrew Howroyd, Aug 09 2018: (Start)

a(n) = 5*a(n-1) - 8*a(n-2) + 3*a(n-3) + 3*a(n-4) - 2*a(n-5).

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

(End)

Example

a(4) = 37 = sum of row 4 terms of triangle A131404: (1 + 11 + 13 + 11 + 1).

Prog

(PARI) Vec((1 - 3*x + 5*x^2 - 6*x^3 + 4*x^4)/((1 - x)^2*(1 - 2*x)*(1 - x - x^2)) + O(x^40)) \\ Andrew Howroyd, Aug 09 2018

Crossrefs

Row sums of A131404.

Cf. A131403.

Sequence in context: A097442 A345025 A329324 * A269963 A176805 A224227

Adjacent sequences: A131402 A131403 A131404 * A131406 A131407 A131408

Keyword

nonn

Author

Gary W. Adamson, Jul 07 2007

Extensions

Terms a(10) and beyond from Andrew Howroyd, Aug 09 2018

Status

approved