close
login
A193024
The number of isomorphism classes of Alexander (a.k.a. affine) quandles of order n.
14
1, 1, 2, 3, 4, 2, 6, 7, 11, 4, 10, 6, 12, 6, 8, 23, 16, 11, 18, 12, 12, 10, 22, 14, 39, 12, 45, 18, 28, 8, 30, 48, 20, 16, 24, 33, 36, 18, 24, 28, 40, 12, 42, 30, 44, 22, 46, 46, 83, 39, 32, 36, 52, 45, 40, 42, 36, 28, 58, 24, 60, 30, 66, 167, 48, 20, 66, 48
OFFSET
1,3
COMMENTS
Nelson enumerated Alexander quandles to order 16 (see the links below). The values of a(n) for n from 1 to 255 were obtained via a GAP program using ideas from Hou (see the link below).
LINKS
W. E. Clark, M. Elhamdadi, M. Saito and T. Yeatman, Quandle Colorings of Knots and Applications, arXiv preprint arXiv:1312.3307 [math.GT], 2013-2014.
M. Elhamdadi, Distributivity in Quandles and Quasigroups, arXiv preprint arXiv:1209.6518 [math.RA], 2012. - From N. J. A. Sloane, Dec 29 2012
Xiang-dong Hou, Finite Modules over  Z[t,t^{-1}], arXiv:1107.2076 [math.RA], 2011.
S. Nelson, Classification of Finite Alexander Quandles, arXiv:math/0202281 [math.GT], 2002-2003.
S. Nelson, Alexander Quandles of Order 16s, arXiv:math/0409460 [math.GT], 2004-2006.
PROG
(GAP)
findY:=function(f, g)
local Y, y;
Y:=[];
for y in g do
Add(Y, Image(f, y^(-1))*y);
od;
Y:=Set(Y);
return Subgroup(g, Y);
end;;
Alex:=[];; k:=8;;
for nn in [1..2^k-1] do
Alex[nn]:=0;
od;
for n in [1..2^k-1] do
LGn:=AllSmallGroups(n, IsAbelian);
for g in LGn do
autg:=AutomorphismGroup(g);;
eautg:=List(ConjugacyClasses(autg), Representative);
for f in eautg do
N2:=findY(f, g);
MM:= ((Size(g)^2)/Size(N2));
for nn in [1..2^k-1] do
if nn mod MM = 0 then
Alex[nn]:=Alex[nn]+1;
fi;
od;
od;
od;
od;
for nn in [1..2^k-1] do
Print(Alex[nn], ", ");
od;;
CROSSREFS
See Index to OEIS under quandles.
Sequence in context: A375126 A345044 A047994 * A382662 A384053 A384051
KEYWORD
nonn
AUTHOR
W. Edwin Clark, Jul 15 2011
STATUS
approved