Number of '2' 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, ...).

A277832

Number of '2' 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) =2a(3) =27a(4) =389a(5) =5121a(6) =63553a(7) =758985a(8) =8824417a(9) =100589849a(10) =1129355281a(11) =12528120713a(12) =137626886149

External references