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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 5 |
| 6 | 9 |
| 7 | 32 |
| 8 | 56 |
| 9 | 144 |
| 10 | 320 |
| 11 | 1458 |
| 12 | 3645 |
| 13 | 9477 |
| 14 | 25515 |
| 15 | 131072 |
| 16 | 327680 |
| 17 | 1114112 |
| 18 | 3411968 |
| 19 | 19531250 |
| 20 | 56640625 |
| 21 | 195312500 |