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 | 4 |
| 3 | 25 |
| 4 | 265 |
| 5 | 3793 |
| 6 | 70789 |
| 7 | 1600429 |
| 8 | 42811078 |
| 9 | 1316981794 |
| 10 | 45858363502 |
| 11 | 1781106761686 |
| 12 | 76349861206627 |
| 13 | 3579325969675135 |
| 14 | 182170488961796899 |
| 15 | 10002072131444031160 |
| 16 | 589261706147357617009 |
| 17 | 37076870479319887575253 |
| 18 | 2481442922857293505594237 |