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 | 14 |
| 3 | 36 |
| 4 | 103 |
| 5 | 248 |
| 6 | 684 |
| 7 | 1624 |
| 8 | 4445 |
| 9 | 10524 |
| 10 | 28762 |
| 11 | 68060 |
| 12 | 185955 |
| 13 | 439984 |
| 14 | 1202072 |
| 15 | 2844144 |
| 16 | 7770361 |
| 17 | 18384884 |
| 18 | 50228454 |
| 19 | 118841812 |
| 20 | 324681887 |
| 21 | 768205608 |
| 22 | 2098776772 |
| 23 | 4965759176 |
| 24 | 13566706389 |
| 25 | 32099171980 |
| 26 | 87696568754 |
| 27 | 207492309516 |
| 28 | 566879531803 |