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.

A053489 Expansion of e.g.f.: (1-x)^(-2x).

Table of values

n a(n)
0 1
1 0
2 4
3 6
4 64
5 300
6 2568
7 20160
8 193856
9 1989792
10 22687200
11 279956160
12 3737966208
13 53589444480
14 821522026752
15 13407498599040
16 232106716968960
17 4248256958023680
18 81968803604600832
19 1662870215019018240
20 35384007384670648320
21 788053048823608565760

List of values

[1, 0, 4, 6, 64, 300, 2568, 20160, 193856, 1989792, 22687200, 279956160, 3737966208, 53589444480, 821522026752, 13407498599040, 232106716968960, 4248256958023680, 81968803604600832, 1662870215019018240, 35384007384670648320, 788053048823608565760]

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

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