cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-5 of 5 results.

A266167 Number of isotopism classes of unordered pairs of orthogonal Latin squares.

Original entry on oeis.org

1, 0, 1, 1, 2, 0, 20, 23362, 1101734942
Offset: 1

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Author

Ian Wanless, Dec 22 2015

Keywords

Comments

The following operations produce things that are counted as equivalent: simultaneous permutation of the rows or columns of both squares; permutation of the symbols within either square; interchanging the squares.
This sequence is also the number of trisotopism classes of *ordered* pairs of orthogonal Latin squares, where the following operations produce things that are counted as equivalent: simultaneous permutation of the rows or columns of both squares; permutation of the symbols within either square; transposing both squares.

Links

Crossrefs

Cf. A072377, A129732, A266166, A266168, A266169.

A266168 Number of isotopism classes of ordered pairs of orthogonal Latin squares.

Original entry on oeis.org

1, 0, 1, 1, 3, 0, 34, 45927, 2203310919
Offset: 1

Views

Author

Ian Wanless, Dec 22 2015

Keywords

Comments

The following operations produce things that are counted as equivalent: simultaneous permutation of the rows or columns of both squares; permutation of the symbols within either square.

Links

Crossrefs

Cf. A129732, A266166, A266167.

A266170 Number of species of maximal pairs of orthogonal Latin squares.

Original entry on oeis.org

0, 0, 1, 0, 0, 0, 5, 2127, 91845941
Offset: 1

Views

Author

Ian Wanless, Dec 22 2015

Keywords

Comments

These pairs are maximal in that they cannot be extended to a triple of MOLS.

Links

Crossrefs

A129732 counts species of all pairs of MOLS whether maximal or not. Cf. A266171, A266177.

A266172 Number of species of triples of orthogonal Latin squares.

Original entry on oeis.org

1, 0, 0, 1, 1, 0, 1, 39, 371
Offset: 1

Views

Author

Ian Wanless, Dec 23 2015

Keywords

Comments

Also the number of strength 2 orthogonal arrays OA(5,n^2) up to isomorphism.

Links

Crossrefs

Cf. A129732, A266173.

A266173 Number of species of sets of four orthogonal Latin squares.

Original entry on oeis.org

1, 0, 0, 0, 1, 0, 1, 1, 96
Offset: 1

Views

Author

Ian Wanless, Dec 23 2015

Keywords

Comments

Also the number of strength 2 orthogonal arrays OA(6,n^2) up to isomorphism.

Links

Crossrefs

Cf. A129732, A266172.
Showing 1-5 of 5 results.

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