Number of n X n binary matrices, symmetric under horizontal and vertical reflection, with no more than 2 ones in any 2 X 2 subblock.

A141504

Number of n X n binary matrices, symmetric under horizontal and vertical reflection, with no more than 2 ones in any 2 X 2 subblock.

Terms

    a(0) =1a(1) =2a(2) =1a(3) =11a(4) =7a(5) =195a(6) =85a(7) =8969a(8) =3573a(9) =1232795a(10) =391285a(11) =471487297a(12) =125714303a(13) =516844071813a(14) =113185189874

External references