Second arithmetic derivative of squares of prime powers: a(n)=A068346(A056798(n)).

Terms

a(0) =0a(1) =4a(2) =5a(3) =80a(4) =7a(5) =9a(6) =640a(7) =216a(8) =13a(9) =15a(10) =5120a(11) =19a(12) =21a(13) =25a(14) =800a(15) =3645a(16) =31a(17) =33a(18) =26624a(19) =39a(20) =43a(21) =45a(22) =49a(23) =1960a(24) =55a(25) =61a(26) =63a(27) =167936a(28) =69a(29) =73