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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 76 |
| 7 | 232 |
| 8 | 764 |
| 9 | 2620 |
| 10 | 8732 |
| 11 | 28068 |
| 12 | 88448 |
| 13 | 273590 |
| 14 | 839026 |
| 15 | 2559590 |
| 16 | 7810344 |
| 17 | 23899859 |
| 18 | 73552737 |
| 19 | 227149812 |
| 20 | 702978992 |
| 21 | 2177474284 |
| 22 | 6745619532 |
| 23 | 20888771872 |
| 24 | 64643999584 |
| 25 | 199916632224 |
| 26 | 617935452464 |
| 27 | 1909553806592 |
| 28 | 5900616453456 |
| 29 | 18234154867712 |