A141513 - OEIS

A141513

Number of n X n binary matrices, symmetric under 90-degree rotation, with no more than 3 ones in any 2 X 2 subblock.

%I #8 Nov 25 2018 12:24:08

%S 1,2,1,7,8,101,207,5120,20417,961969,7321136,661511545,9650955373,

%T 1669696876968,46646811310045,15458287165896835,827194455797432320,

%U 525025121630724209885,53809855627730048960875

%N Number of n X n binary matrices, symmetric under 90-degree rotation, with no more than 3 ones in any 2 X 2 subblock.

%H R. H. Hardin, <a href="/A141513/b141513.txt">Table of n, a(n) for n = 0..25</a>

%K nonn

%O 0,2

%A _R. H. Hardin_, Aug 10 2008