A213830 Antidiagonal sums of the convolution array A213828.

2, 18, 78, 230, 540, 1092, 1988, 3348, 5310, 8030, 11682, 16458, 22568, 30240, 39720, 51272, 65178, 81738, 101270, 124110, 150612, 181148, 216108, 255900, 300950, 351702, 408618, 472178, 542880, 621240

Offset

1,1

Comments

Every term is even.

Links

Clark Kimberling, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).

Formula

a(n) = (2*n + n^2 + 2*n^3 + 3*n^4)/4.

a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5).

G.f.: f(x)/g(x), where f(x) = 2*x*(1 + 4*x + 4*x^2) and g(x) = (1-x)^5.

Mathematica

(See A213828.)
LinearRecurrence[{5, -10, 10, -5, 1}, {2, 18, 78, 230, 540}, 30] (* Harvey P. Dale, Jan 11 2015 *)

Crossrefs

Cf. A213828.

Sequence in context: A034473 A024171 A056664 * A323947 A064057 A176496

Adjacent sequences: A213827 A213828 A213829 * A213831 A213832 A213833

Keyword

nonn,easy

Author

Clark Kimberling, Jul 04 2012

Status

approved