a(n) = Sum_{d|n} d * binomial(d+n/d-1, d).

Terms

a(0) =1a(1) =4a(2) =6a(3) =14a(4) =10a(5) =36a(6) =14a(7) =56a(8) =48a(9) =80a(10) =22a(11) =228a(12) =26a(13) =140a(14) =240a(15) =316a(16) =34a(17) =552a(18) =38a(19) =820a(20) =546a(21) =308a(22) =46a(23) =2088a(24) =680a(25) =416a(26) =1044a(27) =2156a(28) =58a(29) =4380