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 | 688 |
| 9 | 1950 |
| 10 | 5434 |
| 11 | 14910 |
| 12 | 40840 |
| 13 | 112063 |
| 14 | 309829 |
| 15 | 859684 |
| 16 | 2389776 |
| 17 | 6643900 |
| 18 | 18460796 |
| 19 | 51248304 |
| 20 | 142167544 |
| 21 | 394279264 |
| 22 | 1093484420 |
| 23 | 3033005340 |
| 24 | 8413870972 |
| 25 | 23343324312 |
| 26 | 64766314089 |
| 27 | 179693948237 |
| 28 | 498548997886 |
| 29 | 1383158961636 |