a(n) = sigma(2*n)^2 - sigma(n)^2.

Terms

a(0) =8a(1) =40a(2) =128a(3) =176a(4) =288a(5) =640a(6) =512a(7) =736a(8) =1352a(9) =1440a(10) =1152a(11) =2816a(12) =1568a(13) =2560a(14) =4608a(15) =3008a(16) =2592a(17) =6760a(18) =3200a(19) =6336a(20) =8192a(21) =5760a(22) =4608a(23) =11776a(24) =7688a(25) =7840a(26) =12800a(27) =11264a(28) =7200a(29) =23040