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 | 5 |
| 2 | 45 |
| 3 | 585 |
| 4 | 9945 |
| 5 | 69615 |
| 6 | 348075 |
| 7 | 10094175 |
| 8 | 111035925 |
| 9 | 4108329225 |
| 10 | 168441498225 |
| 11 | 56147166075 |
| 12 | 393030162525 |
| 13 | 20830598613825 |
| 14 | 395781373662675 |
| 15 | 24142663793423175 |
| 16 | 24142663793423175 |
| 17 | 555281267248733025 |