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 | 2 |
| 2 | 3 |
| 3 | 10 |
| 4 | 56 |
| 5 | 502 |
| 6 | 6930 |
| 7 | 157172 |
| 8 | 5847270 |
| 9 | 350430420 |
| 10 | 33789991248 |
| 11 | 5280020814732 |
| 12 | 1338210835193414 |
| 13 | 548265785425359340 |
| 14 | 363248986031094300018 |
| 15 | 389399454403643525265020 |
| 16 | 675824289510077938157099920 |