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 | 3 |
| 4 | 7 |
| 5 | 23 |
| 6 | 81 |
| 7 | 325 |
| 8 | 1429 |
| 9 | 6851 |
| 10 | 35443 |
| 11 | 196507 |
| 12 | 1160633 |
| 13 | 7266561 |
| 14 | 48022313 |
| 15 | 333776331 |
| 16 | 2432140759 |
| 17 | 18528143535 |
| 18 | 147201596073 |
| 19 | 1216952016245 |
| 20 | 10448532393869 |
| 21 | 92999784076875 |
| 22 | 856739848236627 |
| 23 | 8156691628658019 |
| 24 | 80147320081510673 |
| 25 | 811770418508099905 |