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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 10 |
| 5 | 52 |
| 6 | 281 |
| 7 | 1570 |
| 8 | 9022 |
| 9 | 53084 |
| 10 | 318634 |
| 11 | 1945396 |
| 12 | 12052532 |
| 13 | 75624616 |
| 14 | 479814937 |
| 15 | 3074251682 |
| 16 | 19869323638 |
| 17 | 129420288076 |
| 18 | 848897059790 |
| 19 | 5603350613308 |
| 20 | 37198680816844 |
| 21 | 248241480270680 |
| 22 | 1664546969372554 |
| 23 | 11210468046615412 |
| 24 | 75806810042727980 |
| 25 | 514537522249147672 |