E.g.f. satisfies y'' + y' + x^3*y = 0 with y(0)=1, y'(0)=0.

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =-6a(6) =6a(7) =-6a(8) =6a(9) =-6a(10) =2022a(11) =-5046a(12) =9366a(13) =-15306a(14) =23226a(15) =-3492978a(16) =14513442a(17) =-40082622a(18) =91510782a(19) =-186272862a(20) =17287893150a(21) =-101669044938a(22) =375834179418