6123456

Appears in sequences

• a(n) is the smallest number not already in the sequence, such that the concatenation of all a(n) displays the periodic digit string 1, 2, 3, 4, 5, 6 (and repeat).at n=41A165304
• a(n) = 8*((9*n + 8)*10^n - 8)/81.at n=6A294329
• Concatenation of the decimal digits of {n, 1..n}.at n=5A357915