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A108994
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Third diagonal of triangle A108990, in which the g.f. of row n, R_n(x), satisfies: [x^k] R_{n+1}(x) = [x^k] (1 + x*R_n(x))^(n+1) for k=0..n+1.
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6
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1, 3, 18, 180, 2670, 54096, 1411228, 45421776, 1747674405, 78485504845, 4037946005808, 234494393383614, 15187062546935643, 1086079262127563445, 85049134680670591560, 7241328591814507465712, 666283956766298002183275
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OFFSET
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0,2
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COMMENTS
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a(n) is divisible by (n+1)*(n+2)/2.
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LINKS
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FORMULA
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PROG
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(PARI) {a(n)=local(F=1+x*O(x^n)); for(m=1, n+2, F=(1+x*F)^m); polcoeff(F, n)}
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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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