Partial sums of Sum_{k=1..n} n/gcd(n,k), or partial sums of Sum_{d|n} d*phi(d) (see A057660).

Terms

a(0) =1a(1) =4a(2) =11a(3) =22a(4) =43a(5) =64a(6) =107a(7) =150a(8) =211a(9) =274a(10) =385a(11) =462a(12) =619a(13) =748a(14) =895a(15) =1066a(16) =1339a(17) =1522a(18) =1865a(19) =2096a(20) =2397a(21) =2730a(22) =3237a(23) =3538a(24) =4059a(25) =4530a(26) =5077a(27) =5550a(28) =6363a(29) =6804