273728

Appears in sequences

• Number of -7..7 arrays x(0..n+1) of n+2 elements with zero sum and no two neighbors summing to zero.at n=3A199831
• Number of -n..n arrays x(0..5) of 6 elements with zero sum and no two neighbors summing to zero.at n=6A199835
• Nonpalindromic positive integers k such that the absolute value of k^2 - reverse(k)^2 is a square.at n=18A256515