|
%I #5 Oct 01 2021 17:52:12
%S 1,6,90,4464,493920,128269440,57943903500
%N Number of n X 4 arrays of permutations of 4 copies of 0..n-1 with row sums equal and column sums equal.
%C Column 4 of A265089.
%e Some solutions for n=4
%e ..3..2..0..1....2..2..0..2....3..3..0..0....3..1..1..1....0..1..3..2
%e ..0..1..2..3....3..0..2..1....1..1..3..1....1..2..0..3....3..2..0..1
%e ..3..2..1..0....1..1..1..3....2..0..2..2....2..0..2..2....3..1..2..0
%e ..0..1..3..2....0..3..3..0....0..2..1..3....0..3..3..0....0..2..1..3
%Y Cf. A265089.
%K nonn
%O 1,2
%A _R. H. Hardin_, Dec 01 2015
| 