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 | 3 |
| 4 | 10 |
| 5 | 31 |
| 6 | 95 |
| 7 | 286 |
| 8 | 853 |
| 9 | 2525 |
| 10 | 7436 |
| 11 | 21815 |
| 12 | 63821 |
| 13 | 186328 |
| 14 | 543165 |
| 15 | 1581591 |
| 16 | 4601410 |
| 17 | 13378731 |
| 18 | 38880803 |
| 19 | 112954430 |
| 20 | 328063121 |