Number of (2+1) X (n+1) arrays of permutations of 0..n*3+2 with each element having index change +-(.,.) 0,0 1,2 or 2,2.

A264018

Number of (2+1) X (n+1) arrays of permutations of 0..n*3+2 with each element having index change +-(.,.) 0,0 1,2 or 2,2.

Terms

    a(0) =1a(1) =5a(2) =25a(3) =105a(4) =441a(5) =1869a(6) =7921a(7) =33553a(8) =142129a(9) =602069a(10) =2550409a(11) =10803705a(12) =45765225a(13) =193864605a(14) =821223649a(15) =3478759201a(16) =14736260449a(17) =62423800997a(18) =264431464441

External references