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 | 1 |
| 3 | 0 |
| 4 | 5 |
| 5 | 4 |
| 6 | 28 |
| 7 | 48 |
| 8 | 183 |
| 9 | 424 |
| 10 | 1315 |
| 11 | 3420 |
| 12 | 9864 |
| 13 | 26756 |
| 14 | 75237 |
| 15 | 207128 |
| 16 | 577345 |
| 17 | 1597624 |
| 18 | 4439764 |
| 19 | 12307388 |
| 20 | 34166643 |
| 21 | 94769936 |
| 22 | 262998791 |
| 23 | 729644824 |
| 24 | 2024614928 |
| 25 | 5617339496 |
| 26 | 15586328073 |
| 27 | 43245649904 |
| 28 | 119991232893 |
| 29 | 332929027020 |