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 | 1 |
| 3 | 6 |
| 4 | 22 |
| 5 | 117 |
| 6 | 705 |
| 7 | 4972 |
| 8 | 39916 |
| 9 | 360105 |
| 10 | 3606865 |
| 11 | 39721266 |
| 12 | 477061026 |
| 13 | 6205806061 |
| 14 | 86925018817 |
| 15 | 1304396077272 |
| 16 | 20877063837400 |
| 17 | 355003736855697 |
| 18 | 6391465311099681 |
| 19 | 121460116022428510 |
| 20 | 2429579599296960430 |
| 21 | 51027940329395658981 |
| 22 | 1122742916106886416001 |