This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A277489 #20 Sep 10 2024 04:27:58 %S A277489 0,1,1,5,26,224,2244,28496,417976,7122384,136770960,2937770472, %T A277489 69626588976,1806936836184,50936933449752,1550292926398680, %U A277489 50661309325357824,1769286989373994752,65762170385201959680,2591979585702305271552,107982615297265761991680 %N A277489 Expansion of e.g.f. -LambertW(-log(1+x)). %H A277489 G. C. Greubel, <a href="/A277489/b277489.txt">Table of n, a(n) for n = 0..395</a> %H A277489 <a href="/index/Res#revert">Index entries for reversions of series</a> %F A277489 a(n) = Sum_{k=1..n} Stirling1(n, k)*k^(k-1). %F A277489 a(n) ~ (exp(exp(-1))-1)^(1/2-n) * exp(-exp(-1)/2+1/2-n) * n^(n-1). %F A277489 E.g.f.: Series_Reversion( exp(x * exp(-x)) - 1 ). - _Seiichi Manyama_, Sep 10 2024 %t A277489 CoefficientList[Series[-LambertW[-Log[1+x]], {x, 0, 20}], x] * Range[0, 20]! %t A277489 Table[Sum[StirlingS1[n, k]*k^(k-1), {k, 1, n}], {n, 0, 20}] %o A277489 (PARI) my(x='x+O('x^50)); concat([0], Vec(serlaplace(-lambertw(-log(1+x))))) \\ _G. C. Greubel_, Jun 21 2017 %Y A277489 Cf. A001865, A052807, A133297. %Y A277489 Cf. A357337, A357338. %K A277489 nonn %O A277489 0,4 %A A277489 _Vaclav Kotesovec_, Oct 17 2016