Number of n X n 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards.
A201370
Number of n X n 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards.
Terms
- a(0) =2a(1) =3a(2) =8a(3) =36a(4) =268a(5) =3739a(6) =115168a(7) =8866257a(8) =1799674094a(9) =976134459840
External references
- oeis: A201370