G.f.: A(x) = Sum_{n>=0} x^(n*(n+1)/2) / Product_{k=1..n} (1-x^k)^(n-k+1).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =5a(6) =8a(7) =13a(8) =21a(9) =34a(10) =55a(11) =88a(12) =141a(13) =224a(14) =356a(15) =563a(16) =890a(17) =1401a(18) =2202a(19) =3448a(20) =5386a(21) =8386a(22) =13025a(23) =20175a(24) =31180a(25) =48077a(26) =73976a(27) =113588a(28) =174057a(29) =266174