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 | 50 |
| 6 | 177 |
| 7 | 649 |
| 8 | 2436 |
| 9 | 9307 |
| 10 | 36080 |
| 11 | 141610 |
| 12 | 561732 |
| 13 | 2248709 |
| 14 | 9073415 |
| 15 | 36863549 |
| 16 | 150676275 |
| 17 | 619169360 |
| 18 | 2556446520 |
| 19 | 10600160707 |
| 20 | 44121921044 |
| 21 | 184291848864 |
| 22 | 772204252280 |
| 23 | 3244999395406 |
| 24 | 13672564904027 |
| 25 | 57749354647408 |
| 26 | 244469827514066 |