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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 6 |
| 7 | 14 |
| 8 | 41 |
| 9 | 157 |
| 10 | 725 |
| 11 | 4196 |
| 12 | 29817 |
| 13 | 246646 |
| 14 | 2297088 |
| 15 | 23503564 |
| 16 | 260265650 |
| 17 | 3090341095 |
| 18 | 39101587595 |
| 19 | 524783295041 |
| 20 | 7443251159470 |
| 21 | 111222017297268 |
| 22 | 1746166043555813 |
| 23 | 28734210790531045 |
| 24 | 494526547845483641 |
| 25 | 8883866458982018870 |
| 26 | 166286444108288113541 |
| 27 | 3237719185652343485853 |
| 28 | 65477290060076644381373 |