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 | 0 |
| 1 | 2 |
| 2 | 6 |
| 3 | 12 |
| 4 | 39 |
| 5 | 104 |
| 6 | 366 |
| 7 | 1172 |
| 8 | 4179 |
| 9 | 14572 |
| 10 | 52740 |
| 11 | 190652 |
| 12 | 700274 |
| 13 | 2581112 |
| 14 | 9591666 |
| 15 | 35791472 |
| 16 | 134236179 |
| 17 | 505290272 |
| 18 | 1908947406 |
| 19 | 7233629132 |
| 20 | 27488079132 |
| 21 | 104715393912 |
| 22 | 399823554006 |
| 23 | 1529755308212 |
| 24 | 5864066561554 |
| 25 | 22517998136936 |
| 26 | 86607703209516 |