Number of non-equivalent binary n X n matrices with two nonadjacent 1's.

Terms

a(0) =0a(1) =1a(2) =6a(3) =17a(4) =43a(5) =84a(6) =159a(7) =262a(8) =426a(9) =635a(10) =940a(11) =1311a(12) =1821a(13) =2422a(14) =3213a(15) =4124a(16) =5284a(17) =6597a(18) =8226a(19) =10045a(20) =12255a(21) =14696a(22) =17611a(23) =20802a(24) =24558a(25) =28639a(26) =33384a(27) =38507a(28) =44401a(29) =50730