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 | 5 |
| 4 | 11 |
| 5 | 26 |
| 6 | 68 |
| 7 | 177 |
| 8 | 497 |
| 9 | 1476 |
| 10 | 4613 |
| 11 | 15216 |
| 12 | 52944 |
| 13 | 193367 |
| 14 | 740226 |
| 15 | 2960520 |
| 16 | 12334829 |
| 17 | 53394755 |
| 18 | 239544624 |
| 19 | 1111261697 |
| 20 | 5320103252 |
| 21 | 26237509076 |
| 22 | 133087001869 |
| 23 | 693339241737 |
| 24 | 3705135967663 |
| 25 | 20286965943329 |
| 26 | 113694201046379 |
| 27 | 651571521170323 |
| 28 | 3815204365835840 |
| 29 | 22806847476040913 |
| 30 | 139088381010541237 |
| 31 | 864777487052916454 |