The OEIS is supported by the many generous donors to the OEIS Foundation.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #6 Mar 31 2012 12:36:19
%S 34,254,3444,76352,2733816,163925231,16307921090,2666369228454,
%T 724501421348158,326444188458835963,242909750685458209759,
%U 299419887986747081985221,611366002048450741040107233
%N Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 1 1 diagonally, vertically, antidiagonally or horizontally
%e Some solutions for n=2
%e ..1..1..0..0....1..0..1..0....0..1..1..0....1..1..0..1....0..1..1..0
%e ..1..1..0..0....0..0..0..1....1..0..1..0....1..1..0..1....1..0..0..0
%e ..0..0..0..1....1..0..0..0....1..1..0..0....0..0..0..0....1..0..0..1
%e ..0..0..1..0....0..1..0..1....0..0..0..0....1..1..0..0....0..0..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_ May 10 2011