|
|
A141508
|
|
Number of n X n binary matrices, symmetric under 180 degree rotation, with no more than 2 ones in any 2 X 2 subblock.
|
|
0
|
|
|
1, 2, 3, 19, 93, 1575, 21225, 1007325, 39296735, 5294789855, 584025270873, 223173910768577, 70041418150889563, 76024730608891641301, 67725956302664583147084, 208747768532396398250753135, 528233319697505378983008951127
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|