53988

Appears in sequences

• Number of squarefree palindromes over {0, 1, 2} of length 2n+1.at n=38A012212
• a(n) = n * (n+1)^2 * (3*n^2 + 4*n + 2) / 12.at n=11A132122
• Triangle related to the o.g.f.s. of the right-hand columns of A028421 (E(x,m=2,n)).at n=23A163937