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A371583
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G.f. satisfies A(x) = ( 1 + x*A(x)^(5/2) / (1 - x) )^2.
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2
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1, 2, 13, 104, 940, 9166, 94044, 1000602, 10939780, 122161128, 1387361151, 15974899766, 186069556707, 2188416960148, 25953579753464, 310022550197360, 3726709235290628, 45047517497268968, 547217895030263028, 6676784544374859088, 81789906534091716353
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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) = 2 * Sum_{k=0..n} binomial(5*k+2,k) * binomial(n-1,n-k)/(5*k+2).
G.f.: A(x) = B(x)^2 where B(x) is the g.f. of A349332.
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PROG
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(PARI) a(n, r=2, s=1, t=5, u=0) = r*sum(k=0, n, binomial(t*k+u*(n-k)+r, k)*binomial(n+(s-1)*k-1, n-k)/(t*k+u*(n-k)+r));
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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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