Expansion of (1 - x)^2 * Sum_{j>=0} (x^j / (1 - Sum_{k=1..j} x^k)).

Terms

a(0) =1a(1) =-1a(2) =1a(3) =0a(4) =1a(5) =1a(6) =3a(7) =4a(8) =9a(9) =15a(10) =29a(11) =53a(12) =100a(13) =186a(14) =352a(15) =663a(16) =1257a(17) =2387a(18) =4547a(19) =8678a(20) =16602a(21) =31818a(22) =61092a(23) =117486a(24) =226277a(25) =436403a(26) =842731a(27) =1629297a(28) =3153466a(29) =6109704