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 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 21 |
| 6 | 52 |
| 7 | 131 |
| 8 | 345 |
| 9 | 915 |
| 10 | 2519 |
| 11 | 6926 |
| 12 | 19711 |
| 13 | 55674 |
| 14 | 162594 |
| 15 | 468929 |
| 16 | 1398129 |
| 17 | 4100003 |
| 18 | 12433282 |
| 19 | 36960316 |
| 20 | 113678461 |
| 21 | 341785050 |
| 22 | 1063890616 |
| 23 | 3229522688 |
| 24 | 10156518859 |
| 25 | 31085477306 |
| 26 | 98635931623 |
| 27 | 304048850048 |
| 28 | 972323924567 |
| 29 | 3015979607106 |
| 30 | 9711570455824 |