Number of n X 2 0..2 arrays with every 1 immediately preceded by 0 to the left or above, and every 2 immediately preceded by 0 1 to the left or above.
A203969
Number of n X 2 0..2 arrays with every 1 immediately preceded by 0 to the left or above, and every 2 immediately preceded by 0 1 to the left or above.
Terms
- a(0) =2a(1) =7a(2) =29a(3) =106a(4) =396a(5) =1488a(6) =5569a(7) =20859a(8) =78133a(9) =292644a(10) =1096125a(11) =4105590a(12) =15377699a(13) =57598086a(14) =215736791a(15) =808054127a(16) =3026612006a(17) =11336343903a(18) =42460908170a(19) =159039700345a(20) =595692067467
External references
- oeis: A203969