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 | 2 |
| 2 | 6 |
| 3 | 18 |
| 4 | 58 |
| 5 | 184 |
| 6 | 586 |
| 7 | 1822 |
| 8 | 5618 |
| 9 | 16980 |
| 10 | 50892 |
| 11 | 150064 |
| 12 | 439210 |
| 13 | 1268924 |
| 14 | 3640342 |
| 15 | 10337596 |
| 16 | 29160638 |
| 17 | 81570368 |
| 18 | 226795202 |
| 19 | 626070664 |
| 20 | 1718783084 |
| 21 | 4689582366 |
| 22 | 12730998988 |
| 23 | 34373603158 |
| 24 | 92385339242 |
| 25 | 247099560046 |
| 26 | 658137847408 |
| 27 | 1745322097886 |
| 28 | 4610549234836 |
| 29 | 12131656526628 |