99999999

Appears in sequences

• a(n) = 10^n - 1.at n=8A002283
• Numbers k such that k*(k+2) is a palindrome.at n=35A028503
• Palindromes of form k*(k+2); or palindromes 1 less than a square.at n=17A028504
• Numbers k such that (k*(k+1)*(k+2)) / (k+(k+1)+(k+2)) is a palindrome.at n=36A032789
• Largest number whose square has n digits.at n=15A049416
• a(n) is the smallest number k such that the letter "N" appears n times when k is written in English.at n=19A060227
• Largest number whose cube has n digits.at n=23A061439
• a(0) = 1; a(n) is obtained by incrementing each digit of a(n-1) by 2.at n=19A061512
• Both n and its reverse are one less than a square.at n=17A066619
• Number of nonempty subsets of the set of vertices of a regular n-gon in the plane such that their center of gravity is the center of the polygon.at n=46A070894
• Nonsquarefree numbers obtained by repeating a single digit.at n=28A077572
• a(1) = 1, a(n+1) > a(n) is the smallest multiple of a(n) using only odd digits.at n=5A078221
• Sum of the forward and reverse concatenations of 1 to n.at n=7A078262
• Palindromes k such that k + 2 is also a palindrome.at n=14A082274
• Palindromes arising in A083457.at n=7A083461
• Palindromes n such that 6n + 1 is also a palindrome.at n=22A083835
• a(n) = A084006(n)^(1/2).at n=22A084007
• Terms of A088753 that are not terms of A063048.at n=11A089521
• Least number with identical digits such that the concatenation a(n) a(n-1) ...a(2)a(1) a(2) ... a(n-1) a(n) is a prime.at n=22A090276
• Least number with identical digits such that the concatenation a(n) a(n-1) ...a(2)a(1) a(2) ... a(n-1) a(n) is a prime.at n=16A090276