1/7 of the number of 7-colorings of an n X n array symmetric about both diagonal and antidiagonal.

A145249

1/7 of the number of 7-colorings of an n X n array symmetric about both diagonal and antidiagonal.

Terms

    a(0) =1a(1) =6a(2) =216a(3) =6696a(4) =1245456a(5) =199480536a(6) =191701832976

External references