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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 19 |
| 5 | 54 |
| 6 | 155 |
| 7 | 432 |
| 8 | 1252 |
| 9 | 3384 |
| 10 | 9714 |
| 11 | 26752 |
| 12 | 75836 |
| 13 | 213058 |
| 14 | 603791 |
| 15 | 1702868 |
| 16 | 4830747 |
| 17 | 13666890 |
| 18 | 38742120 |
| 19 | 109715858 |
| 20 | 310884129 |
| 21 | 880368618 |
| 22 | 2493252951 |
| 23 | 7058102770 |
| 24 | 19978082407 |
| 25 | 56531061316 |
| 26 | 159932660960 |
| 27 | 452354328946 |
| 28 | 1279190479845 |
| 29 | 3616595649500 |