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 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 24 |
| 5 | 267 |
| 6 | 5647 |
| 7 | 237317 |
| 8 | 20035307 |
| 9 | 3404385285 |
| 10 | 1162502511721 |
| 11 | 796392234736238 |
| 12 | 1093228137893084112 |
| 13 | 3004752537725051647790 |
| 14 | 16527844667281561960220731 |
| 15 | 181891583847006693859132403681 |
| 16 | 4004313473818592854334088690859030 |