Sum of the divisors of 9^n+1.

Terms

a(0) =3a(1) =18a(2) =126a(3) =1332a(4) =10476a(5) =109926a(6) =816732a(7) =8906760a(8) =64570086a(9) =706911048a(10) =5357742012a(11) =56496274632a(12) =456919958880