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 | 5 |
| 2 | 70 |
| 3 | 450 |
| 4 | 1680 |
| 5 | 4800 |
| 6 | 11310 |
| 7 | 23590 |
| 8 | 44600 |
| 9 | 78615 |
| 10 | 130550 |
| 11 | 207075 |
| 12 | 315600 |
| 13 | 465790 |
| 14 | 667940 |
| 15 | 935250 |
| 16 | 1281520 |
| 17 | 1723970 |
| 18 | 2280330 |
| 19 | 2972455 |
| 20 | 3822500 |
| 21 | 4857510 |
| 22 | 6104560 |
| 23 | 7596325 |
| 24 | 9365400 |
| 25 | 11450750 |
| 26 | 13890760 |
| 27 | 16731225 |
| 28 | 20017060 |
| 29 | 23801315 |
| 30 | 28135800 |
| 31 | 33081495 |