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 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 36 |
| 5 | 138 |
| 6 | 560 |
| 7 | 2402 |
| 8 | 10898 |
| 9 | 52392 |
| 10 | 267394 |
| 11 | 1450790 |
| 12 | 8371220 |
| 13 | 51327178 |
| 14 | 333759746 |
| 15 | 2295276480 |
| 16 | 16639104002 |
| 17 | 126718172670 |
| 18 | 1010487248556 |
| 19 | 8411744415418 |
| 20 | 72899055533482 |
| 21 | 656136245454232 |
| 22 | 6120474697035762 |