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.

A134648 Number of 2n X n (0,1)-matrices with row sums 2 and column sums 4.

Table of values

n a(n)
1 0
2 1
3 90
4 44730
5 56586600
6 154700988750
7 807998767676100
8 7373018003758407000
9 109829050417159537464000
10 2532230252503738514963235000
11 86574740102712303011539719750000
12 4237239732072431006302896746240010000

List of values

[0, 1, 90, 44730, 56586600, 154700988750, 807998767676100, 7373018003758407000, 109829050417159537464000, 2532230252503738514963235000, 86574740102712303011539719750000, 4237239732072431006302896746240010000]

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

Content is available under The OEIS End-User License Agreement.