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 | 2 |
| 2 | 5 |
| 3 | 16 |
| 4 | 63 |
| 5 | 297 |
| 6 | 1649 |
| 7 | 10641 |
| 8 | 78823 |
| 9 | 662315 |
| 10 | 6241889 |
| 11 | 65294039 |
| 12 | 751035233 |
| 13 | 9420926879 |
| 14 | 127958645921 |
| 15 | 1870319380463 |
| 16 | 29263787708393 |
| 17 | 487891616911031 |
| 18 | 8632986776222945 |
| 19 | 161555987833199807 |
| 20 | 3187606376603319017 |
| 21 | 66128414623822131863 |
| 22 | 1438861202348688524897 |
| 23 | 32763278185929878499887 |