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 | 3 |
| 3 | 19 |
| 4 | 195 |
| 5 | 2551 |
| 6 | 41343 |
| 7 | 826939 |
| 8 | 20616795 |
| 9 | 658486351 |
| 10 | 28264985223 |
| 11 | 1725711709459 |
| 12 | 155998194920835 |
| 13 | 21019550046219271 |
| 14 | 4162663551546902223 |
| 15 | 1192847436856343300779 |
| 16 | 489879387071459457083115 |
| 17 | 286844271719979335180726911 |
| 18 | 238844671940165660117456403543 |