Number of n X n symmetric binary matrices containing no more than three 1s in any 3 X 3 sub-block.

A139012

Number of n X n symmetric binary matrices containing no more than three 1s in any 3 X 3 sub-block.

Terms

    a(0) =1a(1) =2a(2) =7a(3) =20a(4) =146a(5) =1660a(6) =24266a(7) =619885a(8) =24951532a(9) =1491389352a(10) =141842503743

External references