Number of walks of length n along the edges of a dodecahedron between two opposite vertices.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =6a(6) =12a(7) =84a(8) =192a(9) =882a(10) =2220a(11) =8448a(12) =22704a(13) =78078a(14) =218988a(15) =710892a(16) =2048256a(17) =6430794a(18) =18837516a(19) =58008216a(20) =171619248a(21) =522598230a(22) =1555243404a(23) =4705481220a(24) =14051590080a(25) =42357719586a(26) =126740502252a(27) =381253030704