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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 22 |
| 6 | 178 |
| 7 | 2278 |
| 8 | 46380 |
| 9 | 1578060 |
| 10 | 92765486 |
| 11 | 9676866173 |
| 12 | 1821391854302 |
| 13 | 625710416245358 |
| 14 | 395761853562201960 |
| 15 | 464128290507379386872 |
| 16 | 1015085639712281997464676 |
| 17 | 4160440039279630394986003604 |
| 18 | 32088534920274236421098827156776 |