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 | 10 |
| 3 | 20 |
| 4 | 38 |
| 5 | 74 |
| 6 | 148 |
| 7 | 298 |
| 8 | 598 |
| 9 | 1196 |
| 10 | 2390 |
| 11 | 4778 |
| 12 | 9556 |
| 13 | 19114 |
| 14 | 38230 |
| 15 | 76460 |
| 16 | 152918 |
| 17 | 305834 |
| 18 | 611668 |
| 19 | 1223338 |
| 20 | 2446678 |
| 21 | 4893356 |
| 22 | 9786710 |
| 23 | 19573418 |
| 24 | 39146836 |
| 25 | 78293674 |
| 26 | 156587350 |
| 27 | 313174700 |
| 28 | 626349398 |
| 29 | 1252698794 |
| 30 | 2505397588 |
| 31 | 5010795178 |
| 32 | 10021590358 |