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 | 2 |
| 2 | 7 |
| 3 | 18 |
| 4 | 49 |
| 5 | 136 |
| 6 | 377 |
| 7 | 1044 |
| 8 | 2891 |
| 9 | 8006 |
| 10 | 22171 |
| 11 | 61398 |
| 12 | 170029 |
| 13 | 470860 |
| 14 | 1303949 |
| 15 | 3611016 |
| 16 | 9999959 |
| 17 | 27692810 |
| 18 | 76689487 |
| 19 | 212375610 |
| 20 | 588130153 |
| 21 | 1628704336 |
| 22 | 4510358465 |
| 23 | 12490501212 |
| 24 | 34589849507 |
| 25 | 95789405774 |
| 26 | 265268869027 |