a(n) = numerator of fraction a/b, where gcd(a, b) = 1, whose decimal representation has the form (1)(2)(3)...(n-1)(n).(1)(2)(3)...(n-1)(n)... with period (1)(2)(3)...(n-1)(n).

A172505

a(n) = numerator of fraction a/b, where gcd(a, b) = 1, whose decimal representation has the form (1)(2)(3)...(n-1)(n).(1)(2)(3)...(n-1)(n)... with period (1)(2)(3)...(n-1)(n).

Terms

    a(0) =10a(1) =400a(2) =41000a(3) =12340000a(4) =411500000a(5) =41152000000

External references