A230284 - OEIS

%I #15 Jan 08 2021 12:26:20

%S 1,1,2,3,8,15,144,35,5760,315,5600,693,43545600,1001,6706022400,6435,

%T 14014,109395,376610217984000,46189,128047474114560000,323323,2540395,

%U 2028117,26976017466662584320000,96577,3241475864250624,35102025,2126818694000,5386025

%N Denominators to Dirichlet inverse of Euler totient based version of series expansion for x/LambertW(x).

%H G. C. Greubel, <a href="/A230284/b230284.txt">Table of n, a(n) for n = 1..385</a>

%t Clear[nn, n, k, s, x]; nn = 22; Denominator[CoefficientList[1 + Integrate[1 + Expand[Sum[Exp[Limit[Zeta[s]*Sum[(If[n == 1, 0, Table[DivisorSum[m, # MoebiusMu[#] &], {m, nn}][[GCD[n, k]]]])/(k)^(s - 1), {k, 1, n}], s -> 1]]*(-x)^n, {n, 1, nn}]], x], x]]

%Y Cf. A191898, A177885, A230283 (numerators).

%Y Similar to but strictly different from A264235.

%K nonn,frac

%O 1,3

%A _Mats Granvik_, Oct 15 2013