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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 12 |
| 6 | 37 |
| 7 | 128 |
| 8 | 457 |
| 9 | 1872 |
| 10 | 8169 |
| 11 | 37600 |
| 12 | 188685 |
| 13 | 990784 |
| 14 | 5497741 |
| 15 | 32333824 |
| 16 | 197920145 |
| 17 | 1272660224 |
| 18 | 8541537105 |
| 19 | 59527313920 |
| 20 | 432381471509 |
| 21 | 3252626013184 |
| 22 | 25340238127989 |
| 23 | 204354574172160 |
| 24 | 1699894200469849 |
| 25 | 14594815769038848 |
| 26 | 129076687233903673 |