1/4 the number of (n+1)X7 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences.
A209551
1/4 the number of (n+1)X7 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences.
Terms
- a(0) =1909a(1) =90186a(2) =3901194a(3) =174401424a(4) =7751834609a(5) =345350598642
External references
- oeis: A209551