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 | 3 |
| 2 | 6 |
| 3 | 16 |
| 4 | 40 |
| 5 | 102 |
| 6 | 256 |
| 7 | 645 |
| 8 | 1625 |
| 9 | 4096 |
| 10 | 10321 |
| 11 | 26008 |
| 12 | 65536 |
| 13 | 165140 |
| 14 | 416128 |
| 15 | 1048576 |
| 16 | 2642246 |
| 17 | 6658043 |
| 18 | 16777216 |
| 19 | 42275935 |
| 20 | 106528681 |
| 21 | 268435456 |
| 22 | 676414963 |
| 23 | 1704458901 |
| 24 | 4294967296 |
| 25 | 10822639410 |
| 26 | 27271342415 |
| 27 | 68719476736 |
| 28 | 173162230555 |