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 | 1 |
| 1 | 2 |
| 2 | 10 |
| 3 | 53 |
| 4 | 264 |
| 5 | 1294 |
| 6 | 6349 |
| 7 | 31200 |
| 8 | 153366 |
| 9 | 753836 |
| 10 | 3705166 |
| 11 | 18211117 |
| 12 | 89508951 |
| 13 | 439943336 |
| 14 | 2162355196 |
| 15 | 10628140702 |
| 16 | 52238121106 |
| 17 | 256754344524 |
| 18 | 1261967164192 |
| 19 | 6202664757387 |
| 20 | 30486569842400 |
| 21 | 149843813435961 |
| 22 | 736493759087077 |
| 23 | 3619922936674360 |