a(n) = Sum_{i=1..n} (n-i+1)*phi(i).

Terms

a(0) =0a(1) =1a(2) =3a(3) =7a(4) =13a(5) =23a(6) =35a(7) =53a(8) =75a(9) =103a(10) =135a(11) =177a(12) =223a(13) =281a(14) =345a(15) =417a(16) =497a(17) =593a(18) =695a(19) =815a(20) =943a(21) =1083a(22) =1233a(23) =1405a(24) =1585a(25) =1785a(26) =1997a(27) =2227a(28) =2469a(29) =2739