1/4 the number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock having exactly two distinct clockwise edge differences.
A209546
1/4 the number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock having exactly two distinct clockwise edge differences.
Terms
- a(0) =7a(1) =20a(2) =61a(3) =191a(4) =603a(5) =1909a(6) =6049a(7) =19173a(8) =60777a(9) =192665a(10) =610761a(11) =1936161a(12) =6137793a(13) =19457329a(14) =61681409a(15) =195535393a(16) =619864097a(17) =1965022785a(18) =6229292161a(19) =19747394881a(20) =62600949633a(21) =198450424449a(22) =629105008769
External references
- oeis: A209546