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 | 2 |
| 3 | 5 |
| 4 | 19 |
| 5 | 129 |
| 6 | 1306 |
| 7 | 16813 |
| 8 | 262181 |
| 9 | 4783059 |
| 10 | 100000214 |
| 11 | 2357947701 |
| 12 | 61917372083 |
| 13 | 1792160394049 |
| 14 | 56693912393474 |
| 15 | 1946195068811453 |
| 16 | 72057594039243049 |
| 17 | 2862423051509815809 |
| 18 | 121439531096661117354 |
| 19 | 5480386857784802185957 |