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 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 24 |
| 6 | 62 |
| 7 | 154 |
| 8 | 396 |
| 9 | 992 |
| 10 | 2536 |
| 11 | 6376 |
| 12 | 16238 |
| 13 | 40914 |
| 14 | 103954 |
| 15 | 262298 |
| 16 | 665478 |
| 17 | 1680726 |
| 18 | 4260262 |
| 19 | 10766470 |
| 20 | 27274444 |