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

%I #8 Nov 10 2015 10:31:14

%S 0,72,1817,10720,89472,1791696,27783305,317382472,3783068416,

%T 51756812704,698792225489,8925688199152,114042394336256,

%U 1490898399253328,19518200132035505,253177516072868896,3279883039710140160

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

%C Row 2 of A263973.

%H R. H. Hardin, <a href="/A263974/b263974.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=4

%e ..5..3..4..1..9....2..6..4..1..9....6..3..8..9..2....6..5..0..8..2

%e ..7..0.12..2.14...10..0..3.14..7....0..1.11..4.14...10.11..1..3..4

%e ..6.13.10.11..8....5.13..8.11.12....5.13.10..7.12...12.13.14..7..9

%Y Cf. A263973.

%K nonn

%O 1,2

%A _R. H. Hardin_, Oct 30 2015