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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 14 |
| 5 | 46 |
| 6 | 282 |
| 7 | 1394 |
| 8 | 12658 |
| 9 | 83122 |
| 10 | 985730 |
| 11 | 8012962 |
| 12 | 116597538 |
| 13 | 1127575970 |
| 14 | 19410377378 |
| 15 | 217492266658 |
| 16 | 4320408974978 |
| 17 | 55023200887938 |
| 18 | 1238467679662722 |
| 19 | 17665859065690754 |
| 20 | 444247724347355554 |
| 21 | 7015393325151055906 |
| 22 | 194912434760367113570 |
| 23 | 3375509056735963889634 |