|
|
A350009
|
|
a(n) is the number of isotopism classes containing symmetric Latin squares of order n.
|
|
4
|
|
|
1, 1, 1, 2, 1, 6, 7, 415, 3460, 35878418, 6320290037, 4612965997149292, 15859695832489637513
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,4
|
|
COMMENTS
|
Isotopism classes are obtained by permuting rows, permuting columns and permuting symbols. There is a stronger notion of equivalence called "species" (also known as main classes and paratopism classes). For this particular problem the counts for species equal the counts for isotopism classes.
|
|
LINKS
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|