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 | 4 |
| 3 | 25 |
| 4 | 180 |
| 5 | 1640 |
| 6 | 17678 |
| 7 | 213761 |
| 8 | 2572363 |
| 9 | 28717151 |
| 10 | 295374892 |
| 11 | 2863710220 |
| 12 | 27059835840 |
| 13 | 257084859669 |
| 14 | 2498594395926 |
| 15 | 24825380748687 |
| 16 | 249116120158421 |