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A365157
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G.f. satisfies A(x) = ( 1 + x*A(x)^2*(1 + x*A(x))^3 )^2.
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1
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1, 2, 15, 124, 1167, 11772, 124561, 1363964, 15326826, 175739698, 2047974619, 24185317182, 288801732423, 3481242975808, 42303574158234, 517683469595912, 6374096109874427, 78909384182870688, 981600144994348111, 12263583888826309544, 153812133876403777005
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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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If g.f. satisfies A(x) = ( 1 + x*A(x)^2*(1 + x*A(x))^s )^t, then a(n) = Sum_{k=0..n} binomial(t*(n+k+1),k) * binomial(s*k,n-k)/(n+k+1).
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PROG
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(PARI) a(n, s=3, t=2) = sum(k=0, n, binomial(t*(n+k+1), k)*binomial(s*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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