Number of nX6 0..2 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards.
A201698
Number of nX6 0..2 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards.
Terms
- a(0) =3a(1) =48a(2) =2068a(3) =167625a(4) =14268351a(5) =795339012a(6) =27102769900a(7) =615440785548
External references
- oeis: A201698