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 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 21 |
| 6 | 92 |
| 7 | 489 |
| 8 | 3000 |
| 9 | 20970 |
| 10 | 166714 |
| 11 | 1467337 |
| 12 | 14212491 |
| 13 | 149992662 |
| 14 | 1723338952 |
| 15 | 21393028409 |
| 16 | 285061374438 |
| 17 | 4054622024814 |
| 18 | 61301381208116 |
| 19 | 982904573560309 |
| 20 | 16672187358390360 |
| 21 | 298389960090957330 |
| 22 | 5617735345244596804 |
| 23 | 110942937545014894799 |