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 | 5 |
| 3 | 10 |
| 4 | 24 |
| 5 | 48 |
| 6 | 114 |
| 7 | 228 |
| 8 | 540 |
| 9 | 1080 |
| 10 | 2558 |
| 11 | 5116 |
| 12 | 12133 |
| 13 | 24266 |
| 14 | 57658 |
| 15 | 115316 |
| 16 | 274600 |
| 17 | 549200 |
| 18 | 1310817 |
| 19 | 2621634 |
| 20 | 6271788 |
| 21 | 12543576 |
| 22 | 30076629 |
| 23 | 60153258 |
| 24 | 144550655 |
| 25 | 289101310 |
| 26 | 696176322 |
| 27 | 1392352644 |
| 28 | 3359516328 |