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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 0 |
| 11 | 2620 |
| 12 | 18228 |
| 13 | 91600 |
| 14 | 400300 |
| 15 | 1604246 |
| 16 | 6098862 |
| 17 | 22340672 |
| 18 | 79928946 |
| 19 | 281441131 |
| 20 | 981869555 |
| 21 | 3421660163 |
| 22 | 11978105085 |
| 23 | 42029994744 |
| 24 | 147596654412 |
| 25 | 518045934492 |
| 26 | 1815662189788 |
| 27 | 6350004678048 |
| 28 | 22151452791824 |
| 29 | 77058178272192 |