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 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 51 |
| 6 | 190 |
| 7 | 759 |
| 8 | 3206 |
| 9 | 14180 |
| 10 | 65203 |
| 11 | 309998 |
| 12 | 1517330 |
| 13 | 7619541 |
| 14 | 39145113 |
| 15 | 205261890 |
| 16 | 1096393056 |
| 17 | 5955598301 |
| 18 | 32852080738 |
| 19 | 183797522935 |
| 20 | 1041802426740 |
| 21 | 5977047039743 |
| 22 | 34679912608313 |
| 23 | 203345277644481 |
| 24 | 1204104271508239 |
| 25 | 7196256426157901 |