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 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 7 |
| 4 | 24 |
| 5 | 41 |
| 6 | 140 |
| 7 | 239 |
| 8 | 816 |
| 9 | 1393 |
| 10 | 4756 |
| 11 | 8119 |
| 12 | 27720 |
| 13 | 47321 |
| 14 | 161564 |
| 15 | 275807 |
| 16 | 941664 |
| 17 | 1607521 |
| 18 | 5488420 |
| 19 | 9369319 |
| 20 | 31988856 |
| 21 | 54608393 |
| 22 | 186444716 |
| 23 | 318281039 |
| 24 | 1086679440 |
| 25 | 1855077841 |
| 26 | 6333631924 |
| 27 | 10812186007 |
| 28 | 36915112104 |
| 29 | 63018038201 |
| 30 | 215157040700 |