Number of zig-zag paths from top to bottom of a 2n-1 by 2n-1 square whose color is not that of the top right corner.

A153338

Number of zig-zag paths from top to bottom of a 2n-1 by 2n-1 square whose color is not that of the top right corner.

Terms

    a(0) =0a(1) =2a(2) =18a(3) =116a(4) =650a(5) =3372a(6) =16660a(7) =79592a(8) =371034a(9) =1697660a(10) =7654460a(11) =34106712a(12) =150499908a(13) =658707896a(14) =2863150440a(15) =12371226064a(16) =53178791162a(17) =227561427612a(18) =969890051884

External references