999999
domain: N
Appears in sequences
- a(n) = 10^n - 1.at n=6A002283
- Numbers k such that k*(k+2) is a palindrome.at n=27A028503
- Palindromes of form k*(k+2); or palindromes 1 less than a square.at n=11A028504
- Numbers k such that (k*(k+1)*(k+2)) / (k+(k+1)+(k+2)) is a palindrome.at n=21A032789
- Fancy primitive repdigit polygonal numbers.at n=18A033704
- Fancy primitive repdigit polygonal numbers (with multiplicity).at n=20A033705
- Palindromic numbers which are the difference of two positive cubes.at n=24A038808
- Numerators of continued fraction convergents to sqrt(62).at n=11A041108
- Numerators of continued fraction convergents to sqrt(248).at n=11A041464
- Numerators of continued fraction convergents to sqrt(992).at n=5A042920
- Composite palindromes divisible by the sum of their prime factors (counted with multiplicity).at n=25A046348
- Composite palindromes divisible by the palindromic sum of their prime factors (counted with multiplicity).at n=6A046360
- a(n)^3 is smallest cube containing exactly n 9's.at n=10A048374
- Largest number whose square has n digits.at n=11A049416
- The full list of 6-Kaprekar numbers.at n=31A053397
- Largest number that has the same number of digits in base 10 and base n, or 0 if no such number exists.at n=13A055866
- a(n) is the smallest number k such that the letter "N" appears n times when k is written in English.at n=14A060227
- Largest number whose cube has n digits.at n=17A061439
- Palindromes of the form k^3-1.at n=3A062841
- Odd abundant numbers not divisible by 5.at n=25A064001