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 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 15 |
| 6 | 24 |
| 7 | 35 |
| 8 | 119 |
| 9 | 504 |
| 10 | 720 |
| 11 | 2519 |
| 12 | 2519 |
| 13 | 41040 |
| 14 | 83160 |
| 15 | 83160 |
| 16 | 196559 |
| 17 | 524160 |
| 18 | 524160 |
| 19 | 3160079 |
| 20 | 3160079 |
| 21 | 3160079 |
| 22 | 3160079 |
| 23 | 68468400 |
| 24 | 68468400 |
| 25 | 68468400 |
| 26 | 68468400 |
| 27 | 4724319600 |
| 28 | 4724319600 |
| 29 | 26702675999 |
| 30 | 26702675999 |