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 | 4 |
| 4 | 13 |
| 5 | 64 |
| 6 | 315 |
| 7 | 1727 |
| 8 | 9658 |
| 9 | 55657 |
| 10 | 325390 |
| 11 | 1929160 |
| 12 | 11555172 |
| 13 | 69840032 |
| 14 | 425318971 |
| 15 | 2607388905 |
| 16 | 16077392564 |
| 17 | 99646239355 |
| 18 | 620439153165 |
| 19 | 3879069845640 |
| 20 | 24342884609625 |
| 21 | 153279112388352 |
| 22 | 968123122592340 |
| 23 | 6131992590993204 |
| 24 | 38940057166651848 |