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 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 21 |
| 6 | 61 |
| 7 | 141 |
| 8 | 309 |
| 9 | 766 |
| 10 | 2191 |
| 11 | 6436 |
| 12 | 18041 |
| 13 | 48348 |
| 14 | 128311 |
| 15 | 347166 |
| 16 | 960197 |
| 17 | 2674883 |
| 18 | 7413514 |
| 19 | 20411986 |
| 20 | 56130675 |
| 21 | 154907229 |
| 22 | 429349768 |
| 23 | 1192532452 |
| 24 | 3312339849 |
| 25 | 9196063371 |
| 26 | 25538113056 |
| 27 | 70994900341 |
| 28 | 197595884071 |
| 29 | 550414483911 |
| 30 | 1533911418946 |