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A367258
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G.f. satisfies A(x) = 1 + x*A(x) * (1 + x*A(x)^2)^2.
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1
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1, 1, 3, 10, 39, 162, 708, 3202, 14867, 70448, 339324, 1656443, 8176968, 40749277, 204727198, 1035837256, 5273360195, 26992906495, 138840628986, 717245323961, 3719765478096, 19359725932165, 101083353127371, 529341453000447, 2779470724644476, 14630696492685339
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OFFSET
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0,3
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LINKS
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FORMULA
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If g.f. satisfies A(x) = 1 + x*A(x)^t * (1 + x*A(x)^u)^s, then a(n) = Sum_{k=0..n} binomial(t*k+u*(n-k)+1,k) * binomial(s*k,n-k) / (t*k+u*(n-k)+1).
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PROG
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(PARI) a(n, s=2, t=1, u=2) = sum(k=0, n, binomial(t*k+u*(n-k)+1, k)*binomial(s*k, n-k)/(t*k+u*(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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