90909090909
domain: N
Appears in sequences
- a(n) = 9*a(n-1) + 10*a(n-2).at n=12A015585
- a(n)*n = A112909(n).at n=10A112910
- Numbers k such that k*(k+2) gives the concatenation of two numbers m and m-1.at n=6A116279
- Numbers with the property that all pairs of consecutive digits differ by 9.at n=18A198486
- Positive integers k with the property that they cannot be converted to a multiple of 11 by changing at most a single decimal digit.at n=4A353023