a(n) = Sum_{k=1..n} k*k', where n' is the arithmetic derivative of n.

Terms

a(0) =0a(1) =2a(2) =5a(3) =21a(4) =26a(5) =56a(6) =63a(7) =159a(8) =213a(9) =283a(10) =294a(11) =486a(12) =499a(13) =625a(14) =745a(15) =1257a(16) =1274a(17) =1652a(18) =1671a(19) =2151a(20) =2361a(21) =2647a(22) =2670a(23) =3726a(24) =3976a(25) =4366a(26) =5095a(27) =5991a(28) =6020a(29) =6950