Number of n X n binary matrices, symmetric under 180 degree rotation, with no more than 3 ones in any 2 X 2 subblock.

A141514

Number of n X n binary matrices, symmetric under 180 degree rotation, with no more than 3 ones in any 2 X 2 subblock.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =29a(4) =176a(5) =5621a(6) =122557a(7) =14694960a(8) =1181467639a(9) =516777127561

External references