39999999

Appears in sequences

• Triangle T(n,k) = 10^(n-1) -1 + k*floor(9*10^(n-1)/(n+1)), with 1 <= r <= n, read by rows.at n=30A093850
• Numbers k such that k * (sum of the digits of k raised to their own power) + 1 is prime and sets a new record for number of digits.at n=14A109376
• Smallest number whose sum of digits is 3n.at n=22A133195
• Smallest number whose sum of digits is 2n.at n=33A133296
• Minimum number k for which the digital sum of k*n is 3*n.at n=25A147823
• a(n) = 4*10^n - 1.at n=7A198970
• a(n+1) is the smallest integer such that the difference between its digital sum and the digital sum of a(n) is n.at n=11A269306