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 | 9 |
| 5 | 30 |
| 6 | 102 |
| 7 | 378 |
| 8 | 1440 |
| 9 | 5607 |
| 10 | 22155 |
| 11 | 87978 |
| 12 | 350775 |
| 13 | 1400490 |
| 14 | 5597487 |
| 15 | 22379145 |
| 16 | 89498880 |
| 17 | 357952170 |
| 18 | 1431737433 |
| 19 | 5726775978 |
| 20 | 22906819575 |
| 21 | 91626580269 |
| 22 | 366505186047 |
| 23 | 1466017950378 |
| 24 | 5864067254880 |