Half the number of n X n binary matrices, symmetric under horizontal reflection, having equal row sums.
A140217
Half the number of n X n binary matrices, symmetric under horizontal reflection, having equal row sums.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =9a(4) =34a(5) =730a(6) =4376a(7) =905345a(8) =10601986a(9) =10009765626a(10) =200097656252
External references
- oeis: A140217