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 | 23 |
| 3 | 505 |
| 4 | 11087 |
| 5 | 243409 |
| 6 | 5343911 |
| 7 | 117322633 |
| 8 | 2575754015 |
| 9 | 56549265697 |
| 10 | 1241508091319 |
| 11 | 27256628743321 |
| 12 | 598404324261743 |
| 13 | 13137638505015025 |
| 14 | 288429642786068807 |
| 15 | 6332314502788498729 |
| 16 | 139022489418560903231 |
| 17 | 3052162452705551372353 |
| 18 | 67008551470103569288535 |