10000100440domain: NAppears in sequencesa(n) = Sum_{d|10} phi(d)*n^(10/d).at n=10A054609a(n) = Sum_{d|n} phi(d)*10^(n/d).at n=10A054617a(n) = Sum_{d|n} phi(d)*n^(n/d).at n=10A228640