Number of reversible strings with n labeled beads of 4 colors, no palindromes of more than 1 bead.

A032071

Number of reversible strings with n labeled beads of 4 colors, no palindromes of more than 1 bead.

Terms

    a(0) =4a(1) =12a(2) =144a(3) =2880a(4) =57600a(5) =1451520a(6) =40642560a(7) =1316044800a(8) =47377612800

External references