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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 64 |
| 10 | 1644 |
| 11 | 19306 |
| 12 | 146718 |
| 13 | 820218 |
| 14 | 3670288 |
| 15 | 13846830 |
| 16 | 45661556 |
| 17 | 134896662 |
| 18 | 364019248 |
| 19 | 909633276 |
| 20 | 2129318414 |
| 21 | 4709083054 |
| 22 | 9912162234 |
| 23 | 19970298696 |
| 24 | 38707229282 |
| 25 | 72458290216 |
| 26 | 131476840106 |
| 27 | 231906957348 |