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| DATA
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42, 174, 645, 2333, 8398, 30275, 109550, 398180, 1453908, 5332407, 19639521, 72616727, 269473750, 1003347975, 3747412770, 14036374680, 52714429260, 198459284400, 748867149234, 2831788492218, 10729442739596
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| FORMULA
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a(n)= A067323(n+5,5), n>=0.
a(n)= A028364(5+n,n) = sum(C(k)*C(5+n-k),k=0..n), n>=0, with the Catalan numbers C(n):=A000108(n).
G.f.: (c(x)^3)sum(C(4, k)*c(x)^k, k=0..4), with C(n, m) := (m+1)*binomial(2*n-m, n-m)/(n+1) (Catalan convolutions A033184).
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