Number of n X n symmetric binary matrices with each 1 adjacent to exactly 2 horizontally or vertically neighboring 1s.
A191293
Number of n X n symmetric binary matrices with each 1 adjacent to exactly 2 horizontally or vertically neighboring 1s.
Terms
- a(0) =1a(1) =2a(2) =4a(3) =13a(4) =53a(5) =278a(6) =1915a(7) =17298a(8) =206161a(9) =3270381a(10) =68710560a(11) =1908681423a(12) =70045542183
External references
- oeis: A191293