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.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 18 |
| 5 | 312 |
| 6 | 3798 |
| 7 | 41544 |
| 8 | 438270 |
| 9 | 4566120 |
| 10 | 47368110 |
| 11 | 490668936 |
| 12 | 5080145070 |
| 13 | 52588590888 |
| 14 | 544355820750 |
| 15 | 5634640292424 |
| 16 | 58323941179182 |
| 17 | 603707608725096 |
| 18 | 6248936971173390 |
| 19 | 64682313170747016 |
| 20 | 669522088312069614 |
| 21 | 6930176023749038760 |
| 22 | 71733763792342350798 |