9999999999
domain: N
Appears in sequences
- a(n) = 10^n - 1.at n=10A002283
- Palindromes of form k*(k+2); or palindromes 1 less than a square.at n=20A028504
- Palindromic Super-9 Numbers.at n=2A032757
- Fancy primitive repdigit polygonal numbers.at n=21A033704
- Fancy primitive repdigit polygonal numbers (with multiplicity).at n=23A033705
- a(n)^3 is smallest cube containing exactly n 9's.at n=18A048374
- Append d digits d after each digit d in decimal expansion of n.at n=9A048377
- a(n) = n^n - 1.at n=9A048861
- Largest number whose square has n digits.at n=19A049416
- a(n) is the smallest number k such that the letter "N" appears n times when k is written in English.at n=25A060227
- Largest number whose cube has n digits.at n=29A061439
- Both n and its reverse are one less than a square.at n=22A066619
- Palindromes k such that k + 2 is also a palindrome.at n=16A082274
- Palindromes arising in A083457.at n=9A083461
- a(n) = 100^n - 1.at n=5A098609
- a(n) = 10^n - (-1)^n.at n=10A098611
- a(n) = 0^n + 10^n - 1.at n=10A103456
- Largest n-digit number coprime to n.at n=9A108908
- Copies of 1 and 9 alternately such that every partial concatenation is a prime.at n=3A110780
- a(n)*n = A112909(n).at n=9A112910