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.

A055603 Number of n X n binary matrices with no zero rows or columns and with n+2 ones.

Table of values

n a(n)
1 0
2 1
3 90
4 2248
5 43000
6 755100
7 13003620
8 226262400
9 4037765760
10 74481120000
11 1425927888000
12 28389466828800
13 588245898240000
14 12685887076262400
15 284623499160000000
16 6639289429893120000
17 160886197351047168000
18 4046412223559946240000
19 105527367894862577664000

List of values

[0, 1, 90, 2248, 43000, 755100, 13003620, 226262400, 4037765760, 74481120000, 1425927888000, 28389466828800, 588245898240000, 12685887076262400, 284623499160000000, 6639289429893120000, 160886197351047168000, 4046412223559946240000, 105527367894862577664000]

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

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