7000001domain: NAppears in sequencesTurban numbers: without letters r, t, or u.at n=28A072956Smallest n-digit squarefree number beginning with n.at n=6A077513Number of times 1 is used in writing out all numbers 1 through 10^n.at n=7A094797a(n) = 7*10^n + 1.at n=6A199687