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

Terms

a(0) =1a(1) =-1a(2) =-1a(3) =11a(4) =-23a(5) =-101a(6) =991a(7) =-1849a(8) =-24751a(9) =220823a(10) =-174689a(11) =-10924541a(12) =87639289a(13) =105372851a(14) =-7496679553a(15) =52397291519a(16) =238887991201