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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 10 |
| 4 | 6 |
| 5 | 60 |
| 6 | 42 |
| 7 | 210 |
| 8 | 780 |
| 9 | 420 |
| 10 | 2730 |
| 11 | 5460 |
| 12 | 3570 |
| 13 | 10920 |
| 14 | 30030 |
| 15 | 94710 |
| 16 | 231420 |
| 17 | 510510 |
| 18 | 190190 |
| 19 | 1504230 |
| 20 | 2552550 |
| 21 | 285285 |
| 22 | 15120105 |
| 23 | 1141140 |
| 24 | 570570 |
| 25 | 60480420 |
| 26 | 78768690 |
| 27 | 380570190 |
| 28 | 577642065 |
| 29 | 514083570 |