A184268 Number of distinct n X 6 toroidal binary arrays.

14, 362, 14624, 699600, 35792568, 1908897152, 104715443852, 5864063066500, 333599974922264, 19215358463836552, 1117984489446008100, 65588423376054708480, 3874762242361630560584, 230271584688657874664612, 13754889325393505198471808, 825293359523595646115953700

Offset: 1

Author

R. H. Hardin, Jan 10 2011

Keywords

• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 1..550
• S. N. Ethier, Counting toroidal binary arrays, arXiv preprint arXiv:1301.2352, 2013 and J. Int. Seq. 16 (2013) #13.4.7 .

Crossrefs

Column 6 of A184271.

Programs

Maple

with(numtheory):
a:= n-> add(add(phi(c)*phi(d) *2^(6*n/ilcm(c, d)),
        d=divisors(n)), c=[1,2,3,6])/(6*n):
seq(a(n), n=1..25);  # Alois P. Heinz, Aug 25 2012

Formula

a(n) ~ 64^n / (6*n). - Vaclav Kotesovec, Sep 04 2014

Extensions

More terms from Alois P. Heinz, Aug 25 2012