Number of zig-zag paths from top to bottom of a 2n-1 by 2n-1 square whose color is that of the top right corner.

A153337

Number of zig-zag paths from top to bottom of a 2n-1 by 2n-1 square whose color is that of the top right corner.

Terms

    a(0) =1a(1) =4a(2) =24a(3) =136a(4) =720a(5) =3624a(6) =17584a(7) =83024a(8) =383904a(9) =1746280a(10) =7839216a(11) =34812144a(12) =153204064a(13) =669108496a(14) =2903267040a(15) =12526343584a(16) =53779871552a(17) =229895033832a(18) =978965187184

External references