Number of length n+3 0..n arrays with no four elements in a row with pattern abba (possibly a=b) and new values 0..n introduced in 0..n order.
A243026
Number of length n+3 0..n arrays with no four elements in a row with pattern abba (possibly a=b) and new values 0..n introduced in 0..n order.
Terms
- a(0) =6a(1) =32a(2) =147a(3) =672a(4) =3223a(5) =16516a(6) =90634a(7) =530734a(8) =3300512a(9) =21698553a(10) =150209133a(11) =1091147286a(12) =8292645182a(13) =65763764253a(14) =542946198732
External references
- oeis: A243026