Number of length n+2 0..n arrays with no three unequal elements in a row and no three equal elements in a row and new values 0..n introduced in 0..n order.
A243721
Number of length n+2 0..n arrays with no three unequal elements in a row and no three equal elements in a row and new values 0..n introduced in 0..n order.
Terms
- a(0) =3a(1) =6a(2) =12a(3) =25a(4) =53a(5) =116a(6) =259a(7) =594a(8) =1389a(9) =3323a(10) =8095a(11) =20113a(12) =50814a(13) =130632a(14) =341034a(15) =904331a(16) =2432412a(17) =6636112a(18) =18345413a(19) =51381635a(20) =145691912a(21) =418131443a(22) =1213928928a(23) =3564262737a(24) =10579009345a(25) =31733010233a(26) =96162631881a(27) =294324273852
External references
- oeis: A243721