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A113331
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a(n) = Sum_{k=0..n} 6^k*A111146(n,k).
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6
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1, 6, 72, 900, 11520, 149904, 1976400, 26363232, 355648320, 4854292416, 67114780416, 941774874624, 13451571452160, 196362144456192, 2945496714485760, 45717104468689920, 740282299231703040
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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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G.f.: A(x) = 1/(1 - 6/5!*x*Sum(k>=0} (k+5)!*x^k ).
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EXAMPLE
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A(x) = (1 + 6*x + 72*x^2 + 900*x^3 + 11520*x^4 + 149904*x^5 +..)
= 1/(1 - 6/5!*x*(5! + 6!*x + 7!*x^2 + 8!*x^3 + 9!*x^4 +..) ).
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PROG
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(PARI) {a(n)=local(y=6, x=X+X*O(X^n)); polcoeff(1/(1 - y/(y-1)!*x*sum(k=0, n, (y-1+k)!*x^k)), n, X)}
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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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