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A366266
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G.f. A(x) satisfies A(x) = 1 + x + x*A(x)^3.
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17
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1, 2, 6, 30, 170, 1050, 6846, 46374, 323154, 2301618, 16680246, 122607342, 911868282, 6849381194, 51885977838, 395941193718, 3040818657954, 23485437201762, 182297207394150, 1421357996034750, 11126867651367498, 87421958424703098, 689130671539597854
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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} binomial(2*k+1,n-k) * binomial(3*k,k)/(2*k+1).
G.f.: A(x) = 1/B(-x) where B(x) is the g.f. of A366364.
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PROG
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(PARI) a(n) = sum(k=0, n, binomial(2*k+1, n-k)*binomial(3*k, k)/(2*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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