G.f.: A(x) = Sum_{n>=0} x^n / Product_{k=1..n} (1-x^k)^(n-k+1).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =20a(6) =46a(7) =106a(8) =247a(9) =578a(10) =1359a(11) =3204a(12) =7573a(13) =17930a(14) =42512a(15) =100902a(16) =239694a(17) =569768a(18) =1355083a(19) =3224124a(20) =7673612a(21) =18268414a(22) =43500301a(23) =103599089a(24) =246761629a(25) =587822094a(26) =1400398656a(27) =3336473471a(28) =7949650646a(29) =18942098721