Number of permutations of an n X 4 array with each element moving exactly one horizontally or vertically and without 2-loops.

A216796

Number of permutations of an n X 4 array with each element moving exactly one horizontally or vertically and without 2-loops.

Terms

    a(0) =0a(1) =6a(2) =8a(3) =88a(4) =292a(5) =1774a(6) =7676a(7) =39844a(8) =186996a(9) =927134a(10) =4460016a(11) =21812696a(12) =105716132a(13) =514912230a(14) =2501152692a(15) =12167375908a(16) =59142175940a(17) =287602784246

External references