Number of '7' digits in the set of all numbers from 0 to A014824(n) = Sum_{i=1..n} i*10^(n-i) = (0, 1, 12, 123, 1234, 12345, ...).
A277837
Number of '7' digits in the set of all numbers from 0 to A014824(n) = Sum_{i=1..n} i*10^(n-i) = (0, 1, 12, 123, 1234, 12345, ...).
Terms
- a(0) =0a(1) =0a(2) =1a(3) =22a(4) =343a(5) =4664a(6) =58985a(7) =713307a(8) =8367637a(9) =96022049a(10) =1083677281a(11) =12071340713a(12) =133059086145
External references
- oeis: A277837