Number of zig-zag paths from top to bottom of a rectangle of width 9 with 2n-1 rows whose color is not that of the top right corner.
A153367
Number of zig-zag paths from top to bottom of a rectangle of width 9 with 2n-1 rows whose color is not that of the top right corner.
Terms
- a(0) =4a(1) =14a(2) =50a(3) =180a(4) =650a(5) =2350a(6) =8500a(7) =30750a(8) =111250a(9) =402500a(10) =1456250a(11) =5268750a(12) =19062500a(13) =68968750a(14) =249531250a(15) =902812500a(16) =3266406250a(17) =11817968750a(18) =42757812500a(19) =154699218750a(20) =559707031250
External references
- oeis: A153367