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A372016
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G.f. A(x) satisfies A(x) = ( 1 + 4*x/(1 - x*A(x)) )^(1/2).
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1
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1, 2, 0, 6, -2, 38, -32, 314, -436, 3014, -5732, 31954, -74934, 363642, -983868, 4360230, -13021586, 54374950, -173933428, 698713298, -2345075002, 9189017010, -31903354068, 123070336590, -437701811100, 1672475509274, -6052049207112, 22998585552814
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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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a(n) = Sum_{k=0..n} 4^k * binomial(n/2-k/2+1/2,k) * binomial(n-1,n-k)/(n-k+1).
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PROG
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(PARI) a(n) = sum(k=0, n, 4^k*binomial(n/2-k/2+1/2, k)*binomial(n-1, n-k)/(n-k+1));
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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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