1211121

Appears in sequences

• Numbers n which in decimal have the form imj, where m is the middle digit, with property that j is the reversal of i, and i = m*j.at n=20A082945
• Palindromes with digit sum 9.at n=23A121476
• Zeroless palindromes with digit sum 9.at n=13A121477
• Zeroless numbers n such that n and n*product_of_digits(n) are both palindromes.at n=28A229804
• List of privileged words over the alphabet {1,2}.at n=32A235609
• Unique representation of nonnegative numbers by iterated tribonacci A, B and C sequences.at n=46A316713
• Apply the morphism X -> XYX, where Y=1 if X contains an odd number of 1's, otherwise Y = 2 n times to 1, and concatenate the resulting string.at n=2A317956
• a(1) = 1; a(n) is the second smallest number k such that k > a(n-1) and concatenation of a(1), ..., a(n-1), k is a palindrome.at n=3A357314