%I #7 Mar 27 2019 10:03:20
%S 1,-1,3,-11,47,-279,2089,-16057,137409,-1417553,15656651,-187422531,
%T 2501688463,-34832785831,529520417217,-8723102543009,146573712239489,
%U -2670058109819937,52017332039568019,-1041334898093864443,22335551258991482991,-502509800119879530551,11641825391540821682393
%N Expansion of e.g.f. Product_{k>=1} (1 + x^k)^((-1)^k/k).
%e E.g.f.: Sum_{n>=0} a(n)*x^n/n! = ((1 + x^2)^(1/2)*(1 + x^4)^(1/4)*(1 + x^6)^(1/6)* ...)/((1 + x)*(1 + x^3)^(1/3)*(1 + x^5)^(1/5)* ...) = 1 - x + 3*x^2/2! - 11*x^3/3! + 47*x^4/4! - 279*x^5/5! + 2089*x^6/6! - 16057*x^7/7! + ...
%p a:=series(mul((1+x^k)^((-1)^k/k),k=1..100),x=0,23): seq(n!*coeff(a,x,n),n=0..22); # _Paolo P. Lava_, Mar 27 2019
%t nmax = 22; CoefficientList[Series[Product[(1 + x^k)^((-1)^k/k), {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!
%Y Cf. A028342, A168243, A206303, A284474, A294356, A295792, A295834.
%K sign
%O 0,3
%A _Ilya Gutkovskiy_, Nov 28 2017