E.g.f.: (exp(1 - exp(x)) - 1)^2 / 2.

Terms

a(0) =1a(1) =0a(2) =-4a(3) =-5a(4) =22a(5) =98a(6) =-5a(7) =-1458a(8) =-5136a(9) =9053a(10) =161328a(11) =549822a(12) =-1954067a(13) =-30099188a(14) =-114161728a(15) =500200027a(16) =8875931202a(17) =42311243830a(18) =-149028931789