Number of convex polygons of length 2n on square lattice whose leftmost bottom vertex is strictly to the left of the rightmost top vertex.

A005768

Number of convex polygons of length 2n on square lattice whose leftmost bottom vertex is strictly to the left of the rightmost top vertex.

Terms

    a(0) =1a(1) =2a(2) =7a(3) =27a(4) =110a(5) =460a(6) =1948a(7) =8296a(8) =35400a(9) =151056a(10) =643892a(11) =2740216a(12) =11639416a(13) =49340080a(14) =208727176a(15) =881212272a(16) =3713043152a(17) =15615663008a(18) =65555425780a(19) =274734294328

External references