Number of -2..2 arrays x(0..n-1) of n elements with zero sum and no two neighbors equal.
A199698
Number of -2..2 arrays x(0..n-1) of n elements with zero sum and no two neighbors equal.
Terms
- a(0) =1a(1) =4a(2) =14a(3) =52a(4) =200a(5) =708a(6) =2642a(7) =10000a(8) =37984a(9) =144876a(10) =554120a(11) =2128672a(12) =8204180a(13) =31697564a(14) =122734614a(15) =476170124a(16) =1850664202a(17) =7204005752a(18) =28081918548a(19) =109604285492a(20) =428278469018
External references
- oeis: A199698