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A371043
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E.g.f. satisfies A(x) = 1 + x^2*A(x)*exp(x*A(x)).
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1
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1, 0, 2, 6, 36, 380, 3630, 47082, 725816, 12132360, 235801530, 5083309550, 119757623172, 3103443520476, 87082536196838, 2632399338834930, 85471932351187440, 2961803643600574352, 109154615479427298546, 4264407640037365789014, 175984871341042826680700
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OFFSET
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0,3
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LINKS
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FORMULA
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a(n) = n! * Sum_{k=0..floor(n/2)} k^(n-2*k) * binomial(n-k+1,k)/( (n-k+1)*(n-2*k)! ).
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PROG
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(PARI) a(n) = n!*sum(k=0, n\2, k^(n-2*k)*binomial(n-k+1, k)/((n-k+1)*(n-2*k)!));
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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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