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 | 1 |
| 3 | 4 |
| 4 | 10 |
| 5 | 32 |
| 6 | 101 |
| 7 | 346 |
| 8 | 1220 |
| 9 | 4517 |
| 10 | 17338 |
| 11 | 69107 |
| 12 | 285009 |
| 13 | 1215015 |
| 14 | 5344224 |
| 15 | 24223641 |
| 16 | 113001129 |
| 17 | 541913075 |
| 18 | 2668817544 |
| 19 | 13484234188 |
| 20 | 69831773559 |
| 21 | 370361639587 |
| 22 | 2009988998148 |
| 23 | 11153858854425 |
| 24 | 63242354288220 |
| 25 | 366140089188603 |
| 26 | 2163036956456422 |
| 27 | 13031489297543608 |