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A372088
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G.f. A(x) satisfies A(x) = 1/( 1 - 4*x*(1 + x*A(x)) )^(1/2).
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1
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1, 2, 8, 36, 176, 904, 4808, 26240, 146096, 826496, 4737088, 27447936, 160514144, 946139584, 5615411904, 33529225856, 201268922112, 1213912449280, 7352607996160, 44705058498560, 272757529797120, 1669423083509760, 10247263603251200, 63066403179974656
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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(k,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(k, n-k)/(n-k+1));
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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