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 | 8 |
| 3 | 68 |
| 4 | 466 |
| 5 | 2670 |
| 6 | 13460 |
| 7 | 69420 |
| 8 | 417722 |
| 9 | 3025242 |
| 10 | 21873040 |
| 11 | 136901413 |
| 12 | 722201372 |
| 13 | 3271729383 |
| 14 | 13114173697 |
| 15 | 48104723380 |
| 16 | 167526488628 |
| 17 | 574289772576 |
| 18 | 1988721563904 |
| 19 | 7000834741144 |
| 20 | 24759698208450 |
| 21 | 86342520209963 |
| 22 | 292206955736762 |
| 23 | 950480594161453 |