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 | 9 |
| 3 | 25 |
| 4 | 71 |
| 5 | 199 |
| 6 | 561 |
| 7 | 1577 |
| 8 | 4439 |
| 9 | 12487 |
| 10 | 35137 |
| 11 | 98857 |
| 12 | 278151 |
| 13 | 782599 |
| 14 | 2201937 |
| 15 | 6195369 |
| 16 | 17431351 |
| 17 | 49044935 |
| 18 | 137993185 |
| 19 | 388258473 |
| 20 | 1092406631 |
| 21 | 3073602311 |
| 22 | 8647907569 |
| 23 | 24331808809 |
| 24 | 68460135703 |
| 25 | 192619882695 |