Number of n X n symmetric binary matrices with each 1 adjacent to exactly 3 king-move neighboring 1s.

A191224

Number of n X n symmetric binary matrices with each 1 adjacent to exactly 3 king-move neighboring 1s.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =4a(4) =10a(5) =29a(6) =74a(7) =267a(8) =1270a(9) =6853a(10) =46338a(11) =452697a(12) =5888876a(13) =103743236a(14) =2568916974a(15) =83100685126

External references