Number of (n+1)X4 0..3 arrays with rows and columns of determinants of all 2X2 subblocks lexicographically nondecreasing.

A207297

Number of (n+1)X4 0..3 arrays with rows and columns of determinants of all 2X2 subblocks lexicographically nondecreasing.

Terms

    a(0) =15040a(1) =2019514a(2) =158967751a(3) =8967460486a(4) =380160979265

External references