Number of n X n symmetric 0..2 arrays with no element equal to any horizontal or vertical neighbor and with new values 0..2 introduced in lower triangular row major order.
A193268
Number of n X n symmetric 0..2 arrays with no element equal to any horizontal or vertical neighbor and with new values 0..2 introduced in lower triangular row major order.
Terms
- a(0) =1a(1) =2a(2) =12a(3) =108a(4) =1476a(5) =30744a(6) =978696a(7) =47696148a(8) =3562705944a(9) =408229283700
External references
- oeis: A193268