A166489 - OEIS

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A166489

Number of standard SOLSSOMs of order n.

2, 12, 0, 480, 374400, 3528000, 0

(list; graph; refs; listen; history; text; internal format)

OFFSET

4,1

COMMENTS

A SOLSSOM is a self-orthogonal Latin square with a symmetric orthogonal mate. A SOLSSOM is standard if the self-orthogonal Latin square is idempotent and if the symmetric mate is reduced.

REFERENCES

A.P. Burger, M.P. Kidd and J.H. van Vuuren, Enumeration of self-orthogonal Latin squares with symmetric orthogonal mates, Submitted to LitNet Akademies (Natuurwetenskappe)

LINKS

Table of n, a(n) for n=4..10.

CROSSREFS

Cf. A166487, A166488, A166490

Sequence in context: A327780 A350258 A364781 * A160367 A016736 A287704

Adjacent sequences: A166486 A166487 A166488 * A166490 A166491 A166492

KEYWORD

hard,more,nonn

AUTHOR

Martin P Kidd, Oct 21 2009

EXTENSIONS

Definition and number of order 8 (now includes non-unipotent SOLSSOMs) corrected by Martin P Kidd, Nov 01 2010

STATUS

approved