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 | 6 |
| 4 | 30 |
| 5 | 210 |
| 6 | 1680 |
| 7 | 2310 |
| 8 | 18480 |
| 9 | 30030 |
| 10 | 240240 |
| 11 | 480480 |
| 12 | 3843840 |
| 13 | 4084080 |
| 14 | 8168160 |
| 15 | 65345280 |
| 16 | 77597520 |
| 17 | 155195040 |
| 18 | 1241560320 |
| 19 | 1784742960 |
| 20 | 3569485920 |
| 21 | 28555887360 |
| 22 | 51757545840 |
| 23 | 103515091680 |
| 24 | 828120733440 |
| 25 | 1604483921040 |
| 26 | 3208967842080 |
| 27 | 25671742736640 |
| 28 | 51343485473280 |