608722751

Appears in sequences

• Number of n X n symmetric binary matrices containing no more than one 1 in any 2 X 2 sub-block.at n=11A139006
• Number of n X n binary matrices, symmetric about the diagonal and under 90-degree rotation, with no more than 1 one in any 2 X 2 subblock.at n=21A141486
• Number of n X n binary matrices, symmetric about the diagonal and under 90-degree rotation, with no more than 1 one in any 2 X 2 subblock.at n=24A141486