30000000000
domain: N
Appears in sequences
- Powers of 3 written in base 9.at n=21A004663
- a(n) is root of square starting with digit 9: first term of runs.at n=18A035076
- Expansion of (1-7x)/(1-10x).at n=11A093138
- a(1) = 1; for n>1, a(n) = smallest number > a(n-1) such that last digit of a(n-1) + first digit of a(n) = 3.at n=30A098408
- Length of the cycle for Lucas numbers mod 10^n.at n=10A114307
- a(n) is the minimal difference between two distinct n-digit numbers with property that when one of them is typed into a calculator and rotated 180 degrees, the other one is seen.at n=20A125521
- Complete list of all 5 numbers n such that n is equal to the number of 5's in the decimal digits of all numbers <= n.at n=3A130427
- Complete list of all 9 numbers n such that n is equal to the number of 9's in the decimal digits of all numbers <= n.at n=3A130431
- Numbers n such that the sum of all numbers formed by deleting one digit from n is equal to n.at n=34A131639
- Numbers k such that k and k^2 use only the digits 0, 1, 3 and 9.at n=22A136853
- Numbers k such that k and k^2 use only the digits 0, 3, 5 and 9.at n=16A136942
- Numbers k such that k^4 has exactly 3 different decimal digits.at n=25A155149
- Numbers k such that k^2 contains exactly 2 distinct digits and k^3 contains exactly 3 distinct digits.at n=15A247047