a(n) = Sum_{k=1..n} lcm(k,k')/gcd(k,k'), where n' is arithmetic derivative of n.

Terms

a(0) =0a(1) =2a(2) =5a(3) =6a(4) =11a(5) =41a(6) =48a(7) =54a(8) =60a(9) =130a(10) =141a(11) =153a(12) =166a(13) =292a(14) =412a(15) =414a(16) =431a(17) =473a(18) =492a(19) =522a(20) =732a(21) =1018a(22) =1041a(23) =1107a(24) =1117a(25) =1507a(26) =1508a(27) =1564a(28) =1593a(29) =2523