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 | 3 |
| 2 | 13 |
| 3 | 55 |
| 4 | 233 |
| 5 | 987 |
| 6 | 4181 |
| 7 | 17711 |
| 8 | 75025 |
| 9 | 317811 |
| 10 | 1346269 |
| 11 | 5702887 |
| 12 | 24157817 |
| 13 | 102334155 |
| 14 | 433494437 |
| 15 | 1836311903 |
| 16 | 7778742049 |
| 17 | 32951280099 |
| 18 | 139583862445 |
| 19 | 591286729879 |
| 20 | 2504730781961 |
| 21 | 10610209857723 |
| 22 | 44945570212853 |
| 23 | 190392490709135 |
| 24 | 806515533049393 |
| 25 | 3416454622906707 |