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 1-2 of 2 results.

A363862 Number of equivalence classes of unimodular n X n matrices with elements {0, 1}.

Original entry on oeis.org

1, 2, 7, 49, 831, 39637, 5593528, 2363927011
Offset: 1

Views

Author

Brendan McKay, Jun 25 2023

Keywords

Comments

An integer matrix is unimodular if its determinant is -1 or +1. Two matrices are equivalent if one can be obtained from the other by permuting rows and columns.

Examples

			For n=1, the only example is [1]. For n=2, representatives of the equivalence classes are [[1,0],[0,1]] and [[1,1],[0,1]].

Crossrefs

A306837 gives the total counts rather than equivalence classes.

A363884 Number of connected bipartite graphs on 2n nodes with a distinguished partite set of size n and with a unimodular reduced adjacency matrix.

Original entry on oeis.org

1, 1, 5, 41, 777, 38749, 5552904, 2358289931
Offset: 1

Views

Author

Max Alekseyev, Jun 25 2023

Keywords

Crossrefs

Inverse Euler transform of A363862.
Cf. A306837, A363846.
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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