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 | 0 |
| 2 | 5 |
| 3 | 5 |
| 4 | 45 |
| 5 | 105 |
| 6 | 545 |
| 7 | 1825 |
| 8 | 7965 |
| 9 | 30845 |
| 10 | 128945 |
| 11 | 527785 |
| 12 | 2202785 |
| 13 | 9222985 |
| 14 | 38818505 |
| 15 | 164436125 |
| 16 | 698347645 |
| 17 | 2981306665 |
| 18 | 12756855065 |