Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 1 1 diagonally.
A190419
Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 1 1 diagonally.
Terms
- a(0) =56a(1) =728a(2) =17472a(3) =768768a(4) =62270208a(5) =9278260992
External references
- oeis: A190419