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A077899
Expansion of (1-x)^(-1)/(1+x-2*x^2+x^3).
2
1, 0, 3, -3, 10, -18, 42, -87, 190, -405, 873, -1872, 4024, -8640, 18561, -39864, 85627, -183915, 395034, -848490, 1822474, -3914487, 8407926, -18059373, 38789713, -83316384, 178955184, -384377664, 825604417, -1773314928, 3808901427, -8181135699, 17572253482, -37743426306
OFFSET
0,3
FORMULA
a(n) = (-1)^n * Sum_{k=0..n} binomial(2*k-1,n-k). - Seiichi Manyama, Aug 13 2024
PROG
(PARI) Vec((1-x)^(-1)/(1+x-2*x^2+x^3)+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012
(PARI) a(n) = (-1)^n*sum(k=0, n, binomial(2*k-1, n-k)); \\ Seiichi Manyama, Aug 13 2024
CROSSREFS
Cf. A002478.
Sequence in context: A225860 A024313 A132331 * A049973 A025519 A360651
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Nov 17 2002
STATUS
approved