Number of n X n symmetric binary matrices with each 1 adjacent to no more than 2 horizontally, vertically or diagonally neighboring 1s.
A191601
Number of n X n symmetric binary matrices with each 1 adjacent to no more than 2 horizontally, vertically or diagonally neighboring 1s.
Terms
- a(0) =2a(1) =7a(2) =41a(3) =428a(4) =7588a(5) =235992a(6) =12750773a(7) =1196790145a(8) =195443817921
External references
- oeis: A191601