Sum of the unitary divisors of n!.

Terms

a(0) =1a(1) =3a(2) =12a(3) =36a(4) =216a(5) =1020a(6) =8160a(7) =61920a(8) =507744a(9) =4383392a(10) =52600704a(11) =624249600a(12) =8739494400a(13) =109190390400