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 | 3 |
| 2 | 21 |
| 3 | 171 |
| 4 | 1469 |
| 5 | 12988 |
| 6 | 116985 |
| 7 | 1067545 |
| 8 | 9836541 |
| 9 | 91313469 |
| 10 | 852701256 |
| 11 | 8001080244 |
| 12 | 75375985841 |
| 13 | 712487600698 |
| 14 | 6754115819535 |
| 15 | 64185511063246 |
| 16 | 611287650124125 |
| 17 | 5832863405199183 |
| 18 | 55750924705841643 |
| 19 | 533676328608473118 |
| 20 | 5115556211638071944 |