a(n) = [x^n] exp(Sum_{k>=1} x^k/(k*(1 - x^k)^n)).

Terms

a(0) =1a(1) =1a(2) =3a(3) =10a(4) =45a(5) =216a(6) =1232a(7) =7624a(8) =52215a(9) =385495a(10) =3056680a(11) =25825669a(12) =231503636a(13) =2191866327a(14) =21835650219a(15) =228089127908