Number of n X n nonnegative integer arrays with upper left 0 and lower right n+n-6 and value increasing by 0 or 1 with every step right or down.

A252923

Number of n X n nonnegative integer arrays with upper left 0 and lower right n+n-6 and value increasing by 0 or 1 with every step right or down.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =615a(4) =84910a(5) =8241540a(6) =759337545a(7) =73117894428

External references