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) |
|---|---|
| 8 | 1 |
| 9 | 18 |
| 10 | 190 |
| 11 | 1540 |
| 12 | 10626 |
| 13 | 65780 |
| 14 | 376740 |
| 15 | 2035800 |
| 16 | 10518300 |
| 17 | 52451256 |
| 18 | 254186856 |
| 19 | 1203322288 |
| 20 | 5586853480 |
| 21 | 25518731280 |
| 22 | 114955808528 |
| 23 | 511738760544 |
| 24 | 2254848913647 |
| 25 | 9847379391150 |
| 26 | 42671977361650 |
| 27 | 183649923622620 |
| 28 | 785613562163430 |
| 29 | 3342649210440540 |
| 30 | 14154280149473100 |