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 | 1 |
| 2 | 5 |
| 3 | 37 |
| 4 | 345 |
| 5 | 3851 |
| 6 | 49468 |
| 7 | 713931 |
| 8 | 11391985 |
| 9 | 198523495 |
| 10 | 3741919446 |
| 11 | 75702725440 |
| 12 | 1633591960883 |
| 13 | 37404262517506 |
| 14 | 904734768056239 |
| 15 | 23030071358784701 |
| 16 | 614912094171482849 |
| 17 | 17172036245893988575 |
| 18 | 500281954849350450946 |
| 19 | 15170753984617328108901 |