Expansion of 1/(2 - Product_{k>=1} 1/(1 - k*x^k)).

Terms

a(0) =1a(1) =1a(2) =4a(3) =13a(4) =45a(5) =147a(6) =497a(7) =1643a(8) =5490a(9) =18252a(10) =60812a(11) =202364a(12) =673915a(13) =2243295a(14) =7468973a(15) =24865272a(16) =82783967a(17) =275605513a(18) =917563193a(19) =3054785032a(20) =10170143277a(21) =33858882922a(22) =112724577088a(23) =375287739083