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 | 2 |
| 3 | 6 |
| 4 | 14 |
| 5 | 32 |
| 6 | 102 |
| 7 | 238 |
| 8 | 652 |
| 9 | 1696 |
| 10 | 4480 |
| 11 | 11658 |
| 12 | 30870 |
| 13 | 80644 |
| 14 | 212292 |
| 15 | 556858 |
| 16 | 1463390 |
| 17 | 3840686 |
| 18 | 10090218 |
| 19 | 26490280 |
| 20 | 69575414 |
| 21 | 182693434 |
| 22 | 479789138 |
| 23 | 1259906496 |
| 24 | 3308668718 |
| 25 | 8688615148 |
| 26 | 22817011182 |
| 27 | 59918425698 |
| 28 | 157349755400 |
| 29 | 413208421354 |
| 30 | 1085110433096 |