a(n) = [x^n] Product_{d|n} (1 + x^d)/(1 - x^d).

Terms

a(0) =1a(1) =2a(2) =4a(3) =4a(4) =10a(5) =4a(6) =28a(7) =4a(8) =36a(9) =14a(10) =44a(11) =4a(12) =284a(13) =4a(14) =60a(15) =64a(16) =202a(17) =4a(18) =616a(19) =4a(20) =732a(21) =88a(22) =92a(23) =4a(24) =5740a(25) =22a(26) =108a(27) =112a(28) =1404a(29) =4