Number of length n+3 0..4 arrays with no four elements in a row with pattern abba (possibly a=b) and new values 0..4 introduced in 0..4 order.
A243029
Number of length n+3 0..4 arrays with no four elements in a row with pattern abba (possibly a=b) and new values 0..4 introduced in 0..4 order.
Terms
- a(0) =13a(1) =43a(2) =162a(3) =672a(4) =2962a(5) =13540a(6) =63221a(7) =298775a(8) =1421589a(9) =6789700a(10) =32497044a(11) =155720725a(12) =746674943a(13) =3581570065a(14) =17183126915a(15) =82447803666a(16) =395624032453
External references
- oeis: A243029