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 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 13 |
| 5 | 47 |
| 6 | 173 |
| 7 | 639 |
| 8 | 2357 |
| 9 | 8695 |
| 10 | 32077 |
| 11 | 118335 |
| 12 | 436549 |
| 13 | 1610471 |
| 14 | 5941181 |
| 15 | 21917583 |
| 16 | 80856053 |
| 17 | 298285687 |
| 18 | 1100404333 |
| 19 | 4059496479 |
| 20 | 14975869477 |
| 21 | 55247410055 |
| 22 | 203812962077 |
| 23 | 751885445295 |
| 24 | 2773777080149 |
| 25 | 10232728055191 |