A350009 a(n) is the number of isotopism classes containing symmetric Latin squares of order n.

1, 1, 1, 2, 1, 6, 7, 415, 3460, 35878418, 6320290037, 4612965997149292, 15859695832489637513

Offset: 1

Author

Ian Wanless, Dec 08 2021

Keywords

• nonn
• more

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

• Brendan D. McKay and Ian M. Wanless, Enumeration of Latin squares with conjugate symmetry, J. Combin. Des. 30 (2022), 105-130.

Crossrefs

The odd terms agree with A350010. Cf. A035481