18991

Appears in sequences

• Numbers k such that k*(k+2) is a palindrome.at n=18A028503
• Numbers k such that (k*(k+1)*(k+2)) / (k+(k+1)+(k+2)) is a palindrome.at n=13A032789
• Numbers k such that A084937(3k) > A084937(3k+1).at n=40A249689
• Expansion of 1/(1 + Sum_{k>=1} k^2 * x^k).at n=16A316087