Number of n X n symmetric 0..4 arrays with each element equal to at least two horizontal or vertical neighbors and with new values 0..4 introduced in lower triangular row major order.
A192998
Number of n X n symmetric 0..4 arrays with each element equal to at least two horizontal or vertical neighbors and with new values 0..4 introduced in lower triangular row major order.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =6a(4) =35a(5) =696a(6) =19367a(7) =1427148a(8) =166223667a(9) =40685390643
External references
- oeis: A192998