cp's OEIS Frontend

A264656 Number of n X 1 arrays of permutations of 0..n*1-1 with rows nondecreasing modulo 2 and columns nondecreasing modulo 5.

%I A264656 #19 Sep 15 2022 08:06:53
%S A264656 1,1,1,1,1,2,4,8,16,32,96,288,864,2592,7776,31104,124416,497664,
%T A264656 1990656,7962624,39813120,199065600,995328000,4976640000,24883200000,
%U A264656 149299200000,895795200000,5374771200000,32248627200000,193491763200000,1354442342400000
%N A264656 Number of n X 1 arrays of permutations of 0..n*1-1 with rows nondecreasing modulo 2 and columns nondecreasing modulo 5.
%C A264656 Column 1 of A264659.
%H A264656 R. H. Hardin, <a href="/A264656/b264656.txt">Table of n, a(n) for n = 1..74</a>
%F A264656 a(n) = Product_{i=0..4} floor((n+i)/5)!. - _Alois P. Heinz_, Jul 12 2016
%F A264656 a(n) ~ (2*Pi*n)^2 * n! / 5^(n + 5/2). - _Vaclav Kotesovec_, Oct 02 2018
%e A264656 All solutions for n=8
%e A264656 ..5....0....0....5....5....5....0....0
%e A264656 ..0....5....5....0....0....0....5....5
%e A264656 ..1....6....6....6....6....1....1....1
%e A264656 ..6....1....1....1....1....6....6....6
%e A264656 ..7....7....2....2....7....2....7....2
%e A264656 ..2....2....7....7....2....7....2....7
%e A264656 ..3....3....3....3....3....3....3....3
%e A264656 ..4....4....4....4....4....4....4....4
%t A264656 Table[Product[Floor[(n + i)/5]!, {i, 0, 4}], {n, 1, 30}] (* _Vaclav Kotesovec_, Oct 02 2018 *)
%Y A264656 Cf. A264659.
%Y A264656 Column k=5 of A275062.
%K A264656 nonn
%O A264656 1,6
%A A264656 _R. H. Hardin_, Nov 20 2015