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 | 4 |
| 3 | 13 |
| 4 | 50 |
| 5 | 201 |
| 6 | 841 |
| 7 | 3627 |
| 8 | 15993 |
| 9 | 71803 |
| 10 | 327082 |
| 11 | 1508002 |
| 12 | 7023446 |
| 13 | 32995626 |
| 14 | 156173668 |
| 15 | 744029238 |
| 16 | 3565030063 |
| 17 | 17169013899 |
| 18 | 83061503584 |
| 19 | 403483653745 |
| 20 | 1967217524551 |
| 21 | 9623463731721 |
| 22 | 47220968518786 |
| 23 | 232354408276613 |
| 24 | 1146254897566224 |
| 25 | 5668118931395946 |