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 | 3 |
| 2 | 7 |
| 3 | 17 |
| 4 | 42 |
| 5 | 112 |
| 6 | 308 |
| 7 | 882 |
| 8 | 2563 |
| 9 | 7565 |
| 10 | 22449 |
| 11 | 66979 |
| 12 | 200204 |
| 13 | 599514 |
| 14 | 1796350 |
| 15 | 5385764 |
| 16 | 16150725 |
| 17 | 48442327 |
| 18 | 145307291 |
| 19 | 435892341 |
| 20 | 1307617966 |
| 21 | 3922765316 |
| 22 | 11768118792 |
| 23 | 35304090646 |
| 24 | 105911740487 |
| 25 | 317734424289 |
| 26 | 953201678533 |
| 27 | 2859602644103 |
| 28 | 8578803149328 |