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 | 5 |
| 4 | 18 |
| 5 | 91 |
| 6 | 604 |
| 7 | 5123 |
| 8 | 53808 |
| 9 | 679389 |
| 10 | 10107934 |
| 11 | 174544505 |
| 12 | 3451802006 |
| 13 | 77302457079 |
| 14 | 1942469215432 |
| 15 | 54339334903015 |
| 16 | 1680597906265988 |
| 17 | 57116435383949097 |
| 18 | 2121725700531106842 |
| 19 | 85740960774906267853 |
| 20 | 3753239245360442525498 |
| 21 | 177284859933198522968819 |
| 22 | 9004760569281510790598100 |