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 | 21 |
| 2 | 266 |
| 3 | 2646 |
| 4 | 22806 |
| 5 | 178794 |
| 6 | 1310694 |
| 7 | 9140274 |
| 8 | 61330269 |
| 9 | 399107709 |
| 10 | 2533330800 |
| 11 | 15751925280 |
| 12 | 96257031780 |
| 13 | 579556206180 |
| 14 | 3445117599480 |
| 15 | 20252115155160 |
| 16 | 117890464642335 |
| 17 | 680320688005035 |
| 18 | 3895668955041710 |
| 19 | 22152779612619810 |
| 20 | 125183331416173030 |