a(n) = Sum_{d|n} d^2*2^(d-1)*(n/d-1) for n > 0.

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =11a(5) =4a(6) =57a(7) =6a(8) =159a(9) =80a(10) =441a(11) =10a(12) =1567a(13) =12a(14) =3197a(15) =958a(16) =8647a(17) =16a(18) =23301a(19) =18a(20) =53003a(21) =6508a(22) =124005a(23) =22a(24) =315755a(25) =1624a(26) =692345a(27) =41786a(28) =1615939a(29) =28