9999992
domain: N
Appears in sequences
- {Concatenation of n-1 and n+1}/n where n is a member of A069871.at n=13A077192
- Numbers k such that k concatenated with itself gives the product of two numbers which differ by 9.at n=16A116162
- Numbers k such that k * (k+9) is the concatenation of a number m with itself.at n=16A116293
- a(n) = 10^n minus its binary weight.at n=7A218451