11111112

Appears in sequences

• Kaprekar numbers: numbers k such that k = q + r and k^2 = q*10^m + r, for some m >= 1, q >= 0 and 0 <= r < 10^m. Here q and r must both have the same number of digits.at n=36A045913
• a(n) = A047848(7,n).at n=8A047855
• a(n) = ceiling(10^(n-1)/n).at n=8A066559
• a(1) = 1, then the smallest number not included earlier and not a string of 1's such that the concatenation a(n), a(n+1) is a palindrome.at n=27A083122
• A Jacobsthal sequence (A078008) to base 4.at n=16A092900
• Keep only the first digit of each integer and concatenate them. The result is the concatenation of all integers of the sequence.at n=34A106000
• An erroneous sequence.at n=1A108717
• Start with a(1) = 1. For n>1, choose a(n) to be the smallest number > a(n-1) consistent with the condition that "the a(n)-th digit is a 1" is true for all n.at n=44A114134
• Numbers k such that the concatenation of k with 8*k gives a square.at n=16A115549
• Smallest number whose sum of cubes of digits is n.at n=15A165370
• Table T(n,k) = ceiling(10^n/(10^k-1)), n >= 0, k >= 1, read by antidiagonals.at n=36A176088
• Numbers with digital product = 2.at n=28A199986
• Composite numbers whose product of digits is 2.at n=21A201015
• Pseudoprimes to base 3, written in base 3.at n=14A258189
• A base-3/2 sorted Fibonacci sequence that starts with a(0) = 0 and a(1) = 1. The terms are interpreted as numbers written in base 3/2. To get a(n+2), add a(n) and a(n+1), write the result in base 3/2 and sort the "digits" into increasing order, omitting all zeros.at n=17A305753
• A base-3/2 sorted Fibonacci sequence that starts with a(0) = 0 and a(1) = 1. The terms are interpreted as numbers written in base 3/2. To get a(n+2), add a(n) and a(n+1), write the result in base 3/2 and sort the "digits" into increasing order, omitting all zeros.at n=18A305753
• The Wythoff representation of n: an alternative way of presenting A189921.at n=35A317208
• a(n) is the smallest Niven (or Harshad) number with exactly n digits and not containing the digit 0.at n=7A348150
• Kaprekar numbers that are the concatenation of two consecutive numbers.at n=7A381918
• Kaprekar numbers (A006886) that are divisible by the sum of their digits.at n=25A382165