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 | 2 |
| 1 | 11 |
| 2 | 78 |
| 3 | 532 |
| 4 | 3649 |
| 5 | 25008 |
| 6 | 171410 |
| 7 | 1174859 |
| 8 | 8052606 |
| 9 | 55193380 |
| 10 | 378301057 |
| 11 | 2592914016 |
| 12 | 17772097058 |
| 13 | 121811765387 |
| 14 | 834910260654 |
| 15 | 5722560059188 |
| 16 | 39223010153665 |
| 17 | 268838511016464 |
| 18 | 1842646566961586 |
| 19 | 12629687457714635 |
| 20 | 86565165637040862 |
| 21 | 593326472001571396 |