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 | 0 |
| 4 | 0 |
| 5 | 3 |
| 6 | 11 |
| 7 | 60 |
| 8 | 199 |
| 9 | 748 |
| 10 | 2181 |
| 11 | 5391 |
| 12 | 17193 |
| 13 | 31881 |
| 14 | 85942 |
| 15 | 218760 |
| 16 | 430339 |
| 17 | 728315 |
| 18 | 2344106 |
| 19 | 3096983 |
| 20 | 9344528 |
| 21 | 17859116 |
| 22 | 31658109 |
| 23 | 49644736 |
| 24 | 172596719 |
| 25 | 228795554 |