Number of 7's appearing in the sequence of consecutive natural numbers from 1 to A007908(n), where A007908 = (1, 12, 123, 1234, ...).

A277635

Number of 7's appearing in the sequence of consecutive natural numbers from 1 to A007908(n), where A007908 = (1, 12, 123, 1234, ...).

Terms

    a(0) =0a(1) =1a(2) =22a(3) =343a(4) =4664a(5) =58985a(6) =713307a(7) =8367637a(8) =96022049

External references