Number of (1+1)X(n+1) arrays of permutations of 0..n*2+1 with each element having index change +-(.,.) 0,0 0,2 or 1,1.

A264111

Number of (1+1)X(n+1) arrays of permutations of 0..n*2+1 with each element having index change +-(.,.) 0,0 0,2 or 1,1.

Terms

    a(0) =2a(1) =9a(2) =45a(3) =144a(4) =512a(5) =1936a(6) =7381a(7) =27225a(8) =101250a(9) =378225a(10) =1413721a(11) =5271616a(12) =19668992a(13) =73410624a(14) =274002345a(15) =1022528529a(16) =3816059522a(17) =14241796921a(18) =53151529861a(19) =198363344400a(20) =740301120000

External references