Number of nX2 0..2 arrays with every 1 immediately preceded by 0 to the left or above, no 0 immediately preceded by a 0, and every 2 immediately preceded by 0 1 to the left or above.
A203175
Number of nX2 0..2 arrays with every 1 immediately preceded by 0 to the left or above, no 0 immediately preceded by a 0, and every 2 immediately preceded by 0 1 to the left or above.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =4a(4) =6a(5) =10a(6) =18a(7) =30a(8) =50a(9) =86a(10) =146a(11) =246a(12) =418a(13) =710a(14) =1202a(15) =2038a(16) =3458a(17) =5862a(18) =9938a(19) =16854a(20) =28578a(21) =48454a(22) =82162a(23) =139318a(24) =236226a(25) =400550a(26) =679186a(27) =1151638a(28) =1952738a(29) =3311110
External references
- oeis: A203175