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A112518 Expansion of 1/(1-x+2x^3+x^4). 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

Row sums of A112517.

LINKS

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

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: A078974 A094641 A200021 * A228715 A308366 A056849

Adjacent sequences:  A112515 A112516 A112517 * A112519 A112520 A112521

KEYWORD

easy,sign

AUTHOR

Paul Barry, Sep 09 2005

STATUS

approved

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Last modified May 17 22:15 EDT 2021. Contains 343992 sequences. (Running on oeis4.)