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 | 1 |
| 1 | 5 |
| 2 | 19 |
| 3 | 72 |
| 4 | 265 |
| 5 | 979 |
| 6 | 3618 |
| 7 | 13374 |
| 8 | 49447 |
| 9 | 182807 |
| 10 | 675843 |
| 11 | 2498594 |
| 12 | 9237316 |
| 13 | 34150422 |
| 14 | 126254366 |
| 15 | 466763346 |
| 16 | 1725627604 |
| 17 | 6379658213 |
| 18 | 23585644300 |
| 19 | 87196304028 |
| 20 | 322365390600 |
| 21 | 1191787269208 |
| 22 | 4406046481612 |
| 23 | 16289186920873 |
| 24 | 60221246337260 |
| 25 | 222638399818776 |