Number of n X n symmetric 0..3 arrays with each element equal to at least two horizontal or vertical neighbors and with new values 0..3 introduced in lower triangular row major order.
A192997
Number of n X n symmetric 0..3 arrays with each element equal to at least two horizontal or vertical neighbors and with new values 0..3 introduced in lower triangular row major order.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =6a(4) =35a(5) =675a(6) =17727a(7) =1019259a(8) =90018848a(9) =14424049245
External references
- oeis: A192997