69999

Appears in sequences

• E-trees with at most 3 colors.at n=7A007142
• Numbers having four 9's in base 10.at n=6A043528
• Smallest number whose sum of digits is n.at n=42A051885
• Numbers k such that 8*10^k + 7*R_k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=16A056724
• Smallest composite number with digit sum n.at n=41A067524
• a(n) is the smallest composite number with the sum of digits = the n-th composite number.at n=27A073866
• 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=13A093850
• Near-repdigit semiprimes with 9 as repeated digit.at n=31A105990
• Smallest number whose sum of digits is 3n.at n=14A133195
• Smallest number whose sum of digits is 2n.at n=21A133296
• a(1)=0, a(n+1) is the smallest nonprime with sum of digits > sum of digits of a(n).at n=38A156673
• The smallest composite number larger than the n-th composite number, which has a sum of digits equal to the n-th composite number.at n=27A161551
• The smallest number larger than n with digital sum equal to n.at n=41A161561
• Lexicographically earliest injective sequence such that a(n) = A007953(a(a(n))), where A007953 = sum of digits (in base 10).at n=41A167152
• a(n) = 7*10^n - 1.at n=4A198699
• Smallest odd number with digit sum equal to n.at n=41A205960
• Least semiprime whose digital sum is n, or 0 if no such integer exists.at n=42A213653
• Numbers m having with m+1 no common digit in decimal representations.at n=39A226637
• The semiprimes which set new records for the sum of their decimal digits.at n=30A257652
• Partial sums of A278742.at n=19A280730