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 | 1 |
| 5 | 5 |
| 6 | 66 |
| 7 | 392 |
| 8 | 4859 |
| 9 | 34659 |
| 10 | 482272 |
| 11 | 4099634 |
| 12 | 65762489 |
| 13 | 653977909 |
| 14 | 12026621478 |
| 15 | 137361430156 |
| 16 | 2862534403223 |
| 17 | 36968414699239 |
| 18 | 862935261673212 |
| 19 | 12440701298168534 |
| 20 | 321935664074780549 |
| 21 | 5126628962937663529 |
| 22 | 145768013651370381026 |
| 23 | 2541561479354892816304 |