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 | 19 |
| 2 | 209 |
| 3 | 1748 |
| 4 | 12217 |
| 5 | 74898 |
| 6 | 414865 |
| 7 | 2116885 |
| 8 | 10087480 |
| 9 | 45348041 |
| 10 | 193814402 |
| 11 | 792340831 |
| 12 | 3113639744 |
| 13 | 11808753973 |
| 14 | 43368768307 |
| 15 | 154674601937 |
| 16 | 537009888061 |
| 17 | 1818759910067 |
| 18 | 6019901796578 |
| 19 | 19503777943838 |
| 20 | 61940839239196 |
| 21 | 193067981970548 |
| 22 | 591298084019937 |