login
A145859
Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in two by two blocks.
0
1, 2, 1, 2, 2, 7, 5, 38, 12, 182, 72, 1536, 513, 21327, 4531, 360939, 68662, 9098657, 1429824, 345351393, 40840428, 18058986880, 1747979822, 1362075540043, 106711196102, 149443289019658, 9237029528023, 23324890541218597
OFFSET
1,2
EXAMPLE
Maximal 7 X 7 example
.0.0.0.0.0.0.0
.1.1.0.0.0.1.1
.1.1.0.0.0.1.1
.0.0.0.0.0.0.0
.1.1.0.0.0.1.1
.1.1.0.0.0.1.1
.0.0.0.0.0.0.0
CROSSREFS
Sequence in context: A077014 A093655 A023140 * A145863 A240492 A110775
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 22 2008
STATUS
approved