A201370 - OEIS

%I #6 Dec 18 2015 18:17:55

%S 2,3,8,36,268,3739,115168,8866257,1799674094,976134459840

%N Number of n X n 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards

%C Diagonal of A201375

%e Some solutions for n=5

%e ..0..1..1..1..1....0..0..0..0..1....0..1..1..1..1....0..0..1..1..1

%e ..1..0..1..1..1....0..0..0..1..0....1..0..0..1..1....0..1..0..0..1

%e ..1..1..0..0..1....0..1..1..0..0....1..0..0..1..1....0..1..1..1..0

%e ..1..1..0..1..0....1..0..1..0..0....1..1..1..0..0....1..0..1..1..0

%e ..1..1..1..0..0....1..1..0..0..0....1..1..1..0..0....1..1..0..0..0

%K nonn

%O 1,1

%A _R. H. Hardin_ Nov 30 2011