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) |
|---|---|
| 4 | 1 |
| 5 | 4 |
| 6 | 19 |
| 7 | 69 |
| 8 | 265 |
| 9 | 929 |
| 10 | 3356 |
| 11 | 11626 |
| 12 | 41117 |
| 13 | 142206 |
| 14 | 499836 |
| 15 | 1734328 |
| 16 | 6099193 |
| 17 | 21282265 |
| 18 | 75125770 |
| 19 | 263906332 |
| 20 | 936517637 |
| 21 | 3313246237 |
| 22 | 11827430209 |
| 23 | 42139231729 |
| 24 | 151339387003 |
| 25 | 542857007499 |
| 26 | 1961171657524 |
| 27 | 7079621540798 |
| 28 | 25720257983591 |
| 29 | 93396276789196 |