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 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 7 |
| 7 | 12 |
| 8 | 41 |
| 9 | 86 |
| 10 | 247 |
| 11 | 585 |
| 12 | 1548 |
| 13 | 3849 |
| 14 | 9896 |
| 15 | 25001 |
| 16 | 63724 |
| 17 | 161721 |
| 18 | 411257 |
| 19 | 1044878 |
| 20 | 2655719 |
| 21 | 6748972 |
| 22 | 17151849 |
| 23 | 43589578 |
| 24 | 110777391 |
| 25 | 281529169 |
| 26 | 715471992 |
| 27 | 1818293377 |
| 28 | 4620978640 |
| 29 | 11743694657 |
| 30 | 29845241080 |
| 31 | 75848270001 |