Number of zig-zag paths from top to bottom of a rectangle of width 9 with n rows whose color is not that of the top right corner.

A153364

Number of zig-zag paths from top to bottom of a rectangle of width 9 with n rows whose color is not that of the top right corner.

Terms

    a(0) =4a(1) =8a(2) =14a(3) =28a(4) =50a(5) =100a(6) =180a(7) =360a(8) =650a(9) =1300a(10) =2350a(11) =4700a(12) =8500a(13) =17000a(14) =30750a(15) =61500a(16) =111250a(17) =222500a(18) =402500a(19) =805000a(20) =1456250a(21) =2912500a(22) =5268750a(23) =10537500a(24) =19062500a(25) =38125000a(26) =68968750a(27) =137937500a(28) =249531250a(29) =499062500

External references