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.

A023999 Absolute value of determinant of n X n matrix whose entries are the integers from 1 to n^2 spiraling inward, starting in a corner.

Table of values

n a(n)
1 1
2 5
3 48
4 660
5 11760
6 257040
7 6652800
8 198918720
9 6745939200
10 255826771200
11 10727081164800
12 492775291008000
13 24610605962342400
14 1327677426915840000
15 76940526008586240000
16 4766815315895592960000
17 314406967644177408000000
18 21995911456386651463680000

List of values

[1, 5, 48, 660, 11760, 257040, 6652800, 198918720, 6745939200, 255826771200, 10727081164800, 492775291008000, 24610605962342400, 1327677426915840000, 76940526008586240000, 4766815315895592960000, 314406967644177408000000, 21995911456386651463680000]

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

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