G.f.: Product((1+x^i)/(1-x^i),i=1..n-1)/(1-x^n), with n = 5.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =14a(5) =23a(6) =36a(7) =54a(8) =78a(9) =110a(10) =151a(11) =202a(12) =266a(13) =344a(14) =438a(15) =551a(16) =684a(17) =840a(18) =1022a(19) =1232a(20) =1473a(21) =1748a(22) =2060a(23) =2412a(24) =2808a(25) =3251a(26) =3744a(27) =4292a(28) =4898a(29) =5566