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 | 24 |
| 5 | 119 |
| 6 | 708 |
| 7 | 4914 |
| 8 | 38977 |
| 9 | 347794 |
| 10 | 3448202 |
| 11 | 37605875 |
| 12 | 447411544 |
| 13 | 5766612686 |
| 14 | 80042208149 |
| 15 | 1190366133003 |
| 16 | 18882991058982 |
| 17 | 318265784348321 |
| 18 | 5679795502722184 |
| 19 | 106993290279989932 |
| 20 | 2121567147336853153 |
| 21 | 44171924298572910714 |
| 22 | 963472321485580749448 |