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A078001
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Expansion of (1-x)/(1-2*x+x^2+x^3).
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2
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1, 1, 1, 0, -2, -5, -8, -9, -5, 7, 28, 54, 73, 64, 1, -135, -335, -536, -602, -333, 472, 1879, 3619, 4887, 4276, 46, -9071, -22464, -35903, -40271, -22175, 31824, 126094, 242539, 327160, 285687, 1675, -609497, -1506356, -2404890, -2693927, -1476608, 2145601, 8461737, 16254481, 21901624
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history;
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OFFSET
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0,5
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LINKS
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Table of n, a(n) for n=0..45.
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FORMULA
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a(n) = Sum_{k=0..floor(n/3)} (-1)^k*binomial(n-k, 2*k). - Vladeta Jovovic, Feb 10 2003
a(0)=1, a(n+1)=a(n) - Sum_{k=0..n-2} a(k). - Alex Ratushnyak, May 03 2012
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PROG
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(Python)
a = [1]*1000
for n in range(55):
. print a[n],
. sum=0
. for k in range(n-1):
. . sum+=a[k]
. a[n+1] = a[n]-sum
# from Alex Ratushnyak, May 03 2012
(PARI) Vec((1-x)/(1-2*x+x^2+x^3)+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012
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CROSSREFS
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Cf. A005251, A077856.
Sequence in context: A011279 A185094 A071099 * A072955 A153129 A076871
Adjacent sequences: A077998 A077999 A078000 * A078002 A078003 A078004
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KEYWORD
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sign,easy
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AUTHOR
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N. J. A. Sloane, Nov 17 2002
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STATUS
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approved
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