A089064 Expansion of e.g.f. log(1-log(1-x)).
0, 1, 0, 1, 1, 8, 26, 194, 1142, 9736, 81384, 823392, 8738016, 104336880, 1328270880, 18419317968, 272291315376, 4312675967232, 72478365279360, 1292173575000192, 24314102888206464, 482046102448383744, 10037081891973037824
Offset: 0
References
- G. H. Hardy, A Course of Pure Mathematics, 10th ed., Cambridge University Press, 1960, p. 428.
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..451
- G. H. Hardy, A Course of Pure Mathematics, Cambridge, The University Press, 1908.
- Victor Wang On an alternating sum of factorials and Stirling numbers of the first kind: trees, lattices, and games, arXiv:2504.21176 [math.CO], 2025.
Programs
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Mathematica
nmax = 20; CoefficientList[Series[Log[1-Log[1-x]], {x, 0, nmax}], x] * Range[0, nmax]! (* Vaclav Kotesovec, Jul 01 2018 *) Table[(-1)^(n+1) * Sum[(k-1)! * StirlingS1[n, k], {k, 1, n}], {n, 0, 20}] (* Vaclav Kotesovec, Apr 19 2024 *)
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PARI
a(n)=if(n<0,0,n!*polcoeff(log(1-log(1-x+x*O(x^n))),n))
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PARI
{a(n) = if (n<1, 0, (n-1)!-sum(k=1, n-1, binomial(n-1, k)*(k-1)!*a(n-k)))} \\ Seiichi Manyama, Jun 01 2019
Formula
a(n) = (-1)^(n+1)*Sum_{k=1..n} (k-1)!*Stirling1(n, k).
E.g.f.: log(1-log(1-x)).
a(n) = (n-1)! - Sum_{k=1..n-1} binomial(n-1,k) * (k-1)! * a(n-k). - Seiichi Manyama, Jun 01 2019
Comments