%I #3 Nov 17 2015 18:05:45
%S 1,3,24,316,6080,149824,5728896,259780608,14154310656,1054215834624
%N Number of 2Xn arrays of permutations of 0..n*21 with rows nondecreasing modulo 2 and columns nondecreasing modulo 3.
%C Row 2 of A264560.
%e Some solutions for n=4
%e ..0..2..4..3....6..5..1..3....6..0..7..3....0..2..6..4....6..2..4..0
%e ..6..5..7..1....0..2..4..7....2..4..1..5....7..5..3..1....3..5..1..7
%Y Cf. A264560.
%K nonn
%O 1,2
%A _R. H. Hardin_, Nov 17 2015
