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A193469
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a(n) = A193467(n)/n for n>=1.
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1
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1, 2, 9, 70, 805, 12646, 257179, 6524176, 200811433, 7340612842, 313294235311, 15395868322660, 861109521894637, 54282864059246590, 3824491871326292755, 298974154411140942856, 25767887775430753766353, 2434836258338521063652050
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OFFSET
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1,2
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COMMENTS
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A193467 is defined by the e.g.f.: Sum_{n>=0} x^n * exp(n*(n+1)/2*x).
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LINKS
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FORMULA
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O.g.f.: x * Sum_{k>=0} k! * x^k / (1 - binomial(k+2,2)*x)^(k+1). - Ilya Gutkovskiy, Jul 16 2019
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PROG
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(PARI) {a(n)=local(Egf); Egf=sum(m=0, n, x^m*exp(m*(m+1)/2*x+x*O(x^n))); if(n<1, 0, (n-1)!*polcoeff(Egf, 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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