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 | 1 |
| 3 | 0 |
| 4 | 1 |
| 5 | 3 |
| 6 | 6 |
| 7 | 11 |
| 8 | 23 |
| 9 | 60 |
| 10 | 179 |
| 11 | 553 |
| 12 | 1716 |
| 13 | 5415 |
| 14 | 17801 |
| 15 | 61956 |
| 16 | 228391 |
| 17 | 882309 |
| 18 | 3530322 |
| 19 | 14531621 |
| 20 | 61454091 |
| 21 | 267479778 |
| 22 | 1200680113 |
| 23 | 5561767211 |
| 24 | 26553471186 |
| 25 | 130366882251 |
| 26 | 656668581417 |
| 27 | 3387887246292 |
| 28 | 17886582294921 |
| 29 | 96603394562849 |
| 30 | 533645344137390 |
| 31 | 3014295344076655 |