login
A264656
Number of n X 1 arrays of permutations of 0..n*1-1 with rows nondecreasing modulo 2 and columns nondecreasing modulo 5.
7
1, 1, 1, 1, 1, 2, 4, 8, 16, 32, 96, 288, 864, 2592, 7776, 31104, 124416, 497664, 1990656, 7962624, 39813120, 199065600, 995328000, 4976640000, 24883200000, 149299200000, 895795200000, 5374771200000, 32248627200000, 193491763200000, 1354442342400000
OFFSET
1,6
COMMENTS
Column 1 of A264659.
LINKS
FORMULA
a(n) = Product_{i=0..4} floor((n+i)/5)!. - Alois P. Heinz, Jul 12 2016
a(n) ~ (2*Pi*n)^2 * n! / 5^(n + 5/2). - Vaclav Kotesovec, Oct 02 2018
EXAMPLE
All solutions for n=8
..5....0....0....5....5....5....0....0
..0....5....5....0....0....0....5....5
..1....6....6....6....6....1....1....1
..6....1....1....1....1....6....6....6
..7....7....2....2....7....2....7....2
..2....2....7....7....2....7....2....7
..3....3....3....3....3....3....3....3
..4....4....4....4....4....4....4....4
MATHEMATICA
Table[Product[Floor[(n + i)/5]!, {i, 0, 4}], {n, 1, 30}] (* Vaclav Kotesovec, Oct 02 2018 *)
CROSSREFS
Cf. A264659.
Column k=5 of A275062.
Sequence in context: A035523 A290301 A195458 * A078227 A250073 A260873
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 20 2015
STATUS
approved