a(n) = n * Sum_{d|n} d*2^(d-1).

Terms

a(0) =1a(1) =10a(2) =39a(3) =148a(4) =405a(5) =1254a(6) =3143a(7) =8488a(8) =20853a(9) =52050a(10) =123915a(11) =297804a(12) =692237a(13) =1611974a(14) =3687795a(15) =8405584a(16) =18939921a(17) =42512562a(18) =94634003a(19) =209819940a(20) =462431697a(21) =1015269486a(22) =2218786839a(23) =4832458392a(24) =10485762025a(25) =22684180610a(26) =48922424415a(27) =105229923596