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A364408
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G.f. satisfies A(x) = 1 + x*(1 + 1/A(x)^4).
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10
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1, 2, -8, 72, -768, 9072, -114240, 1502976, -20414208, 284083968, -4029438976, 58040074752, -846682968064, 12483389708288, -185725854932992, 2784798982701056, -42039464045854720, 638415031298588672, -9746180768647217152, 149486708349609050112
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OFFSET
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0,2
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LINKS
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FORMULA
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G.f.: A(x) = 1/B(-x) where B(x) is the g.f. of A349311.
a(n) = (-1)^(n-1) * (1/n) * Sum_{k=0..n} binomial(n,k) * binomial(n+4*k-2,n-1) for n > 0.
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PROG
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(PARI) a(n) = if(n==0, 1, (-1)^(n-1)*sum(k=0, n, binomial(n, k)*binomial(n+4*k-2, n-1))/n);
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CROSSREFS
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KEYWORD
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sign
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AUTHOR
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STATUS
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approved
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