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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 76 |
| 6 | 280 |
| 7 | 1045 |
| 8 | 3936 |
| 9 | 14925 |
| 10 | 56892 |
| 11 | 217791 |
| 12 | 836706 |
| 13 | 3224157 |
| 14 | 12456225 |
| 15 | 48232162 |
| 16 | 187131664 |
| 17 | 727309265 |
| 18 | 2831193004 |
| 19 | 11036424667 |
| 20 | 43076087806 |
| 21 | 168322335246 |
| 22 | 658416150496 |
| 23 | 2577945422410 |
| 24 | 10102468839284 |
| 25 | 39621592646545 |