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 | 2 |
| 2 | 6 |
| 3 | 20 |
| 4 | 56 |
| 5 | 176 |
| 6 | 416 |
| 7 | 1088 |
| 8 | 2432 |
| 9 | 5888 |
| 10 | 14848 |
| 11 | 31744 |
| 12 | 75776 |
| 13 | 167936 |
| 14 | 352256 |
| 15 | 770048 |
| 16 | 1736704 |
| 17 | 3866624 |
| 18 | 7995392 |
| 19 | 17563648 |
| 20 | 37224448 |
| 21 | 76546048 |
| 22 | 165675008 |
| 23 | 348127232 |
| 24 | 746586112 |
| 25 | 1627389952 |
| 26 | 3388997632 |
| 27 | 6912212992 |
| 28 | 14361296896 |