A112518 Expansion of 1/(1-x+2x^3+x^4).

1, 1, 1, -1, -4, -7, -6, 3, 21, 40, 40, -5, -106, -226, -256, -39, 519, 1257, 1591, 592, -2441, -6880, -9655, -5365, 10836, 37026, 57411, 41104, -43784, -195632, -335251, -288787, 146261, 1012395, 1925220, 1921485, -249566, -5112401, -10880591, -12302944

Offset

0,5

Comments

Row sums of A112517.

Links

Table of n, a(n) for n=0..39.

Index entries for linear recurrences with constant coefficients, signature (1, 0, -2, -1).

Formula

a(n)=a(n-1)-2a(n-3)-a(n-4); a(n)=sum{k=0..n, sum{j=0..n, C(j, n-j)C(k, j-k)(-1)^(j-k)}}.

Crossrefs

Sequence in context: A094641 A200021 A351909 * A228715 A351546 A349162

Adjacent sequences: A112515 A112516 A112517 * A112519 A112520 A112521

Keyword

easy,sign

Author

Paul Barry, Sep 09 2005

Status

approved