login
A184270
Number of distinct n X 8 toroidal binary arrays.
2
36, 4150, 699252, 134223976, 27487816992, 5864063066500, 1286742755471400, 288230376353050816, 65588423374144427520, 15111572745224096425720, 3516875111606393874082104, 825293359523595646117352176, 195023169265881489687952047216
OFFSET
1,1
LINKS
S. N. Ethier, Counting toroidal binary arrays, arXiv preprint arXiv:1301.2352, 2013 and J. Int. Seq. 16 (2013) #13.4.7.
FORMULA
a(n) ~ 2^(8*n-3) / n. - Vaclav Kotesovec, Sep 04 2014
MAPLE
with(numtheory):
a:= n-> add(add(phi(c)*phi(d) *2^(8*n/ilcm(c, d)),
d=divisors(n)), c=[1, 2, 4, 8])/(8*n):
seq(a(n), n=1..20); # Alois P. Heinz, Aug 25 2012
CROSSREFS
Column 8 of A184271.
Sequence in context: A003744 A163034 A339121 * A187405 A102794 A075415
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 10 2011
EXTENSIONS
More terms from Alois P. Heinz, Aug 25 2012
STATUS
approved