Number of n X n symmetric binary matrices with each 1 adjacent to no more than 1 horizontally or vertically neighboring 1.
A191506
Number of n X n symmetric binary matrices with each 1 adjacent to no more than 1 horizontally or vertically neighboring 1.
Terms
- a(0) =2a(1) =5a(2) =25a(3) =195a(4) =2475a(5) =53324a(6) =1872113a(7) =109037035a(8) =10508450377
External references
- oeis: A191506