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 | 4 |
| 2 | 12 |
| 3 | 36 |
| 4 | 100 |
| 5 | 268 |
| 6 | 704 |
| 7 | 1812 |
| 8 | 4600 |
| 9 | 11556 |
| 10 | 28788 |
| 11 | 71252 |
| 12 | 175452 |
| 13 | 430284 |
| 14 | 1051848 |
| 15 | 2564708 |
| 16 | 6240752 |
| 17 | 15161092 |
| 18 | 36784284 |
| 19 | 89155268 |
| 20 | 215911636 |
| 21 | 522543436 |
| 22 | 1263991824 |
| 23 | 3056244212 |
| 24 | 7387384808 |
| 25 | 17851786148 |
| 26 | 43130479748 |
| 27 | 104187860340 |
| 28 | 251648811212 |
| 29 | 607755975820 |
| 30 | 1467673342616 |