121222

Appears in sequences

• List of Lyndon words on {1,2} sorted first by length and then lexicographically.at n=21A102659
• n expressed in Fibonacci binary-like number system using only 1's and 2's.at n=36A108960
• Sorted list of strings that can be obtained by starting with 12 and repeatedly doubling any substring in place.at n=26A130838
• Numbers for which the sum of reciprocals of square of digits is an integer.at n=13A182452
• Reversed shortest (x+1,2x)-code of n.at n=18A233137
• a(1) = 1; a(2) = 2; for n > 2, a(n) is the least number > a(n-1) whose decimal representation is uniquely the concatenation of the decimal representations of two distinct earlier terms.at n=38A336528