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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 4 |
| 5 | 15 |
| 6 | 34 |
| 7 | 117 |
| 8 | 151 |
| 9 | 721 |
| 10 | 2314 |
| 11 | 12291 |
| 12 | 26896 |
| 13 | 146771 |
| 14 | 467209 |
| 15 | 2015607 |
| 16 | 2482816 |
| 17 | 14429687 |
| 18 | 60201564 |
| 19 | 435840635 |
| 20 | 1367723469 |
| 21 | 11377628387 |
| 22 | 58255865404 |
| 23 | 419168686215 |
| 24 | 896593237834 |
| 25 | 6695321351053 |
| 26 | 34373199993099 |
| 27 | 281680921295845 |
| 28 | 879415963880634 |