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 | 1 |
| 2 | 7 |
| 3 | 36 |
| 4 | 179 |
| 5 | 965 |
| 6 | 5916 |
| 7 | 41622 |
| 8 | 333306 |
| 9 | 3000249 |
| 10 | 30003205 |
| 11 | 330036256 |
| 12 | 3960436437 |
| 13 | 51485675501 |
| 14 | 720799459394 |
| 15 | 10811991893970 |
| 16 | 172991870307396 |
| 17 | 2940861795230577 |
| 18 | 52935512314156371 |
| 19 | 1005774733968978364 |
| 20 | 20115494679379576135 |
| 21 | 422425388266971109461 |