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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 2 |
| 4 | 99 |
| 5 | 2102 |
| 6 | 19987 |
| 7 | 124676 |
| 8 | 571418 |
| 9 | 2122841 |
| 10 | 6704061 |
| 11 | 18711691 |
| 12 | 47235845 |
| 13 | 109938296 |
| 14 | 238950999 |
| 15 | 490309398 |
| 16 | 957267228 |
| 17 | 1790325363 |
| 18 | 3224010105 |
| 19 | 5615368229 |
| 20 | 9493358359 |
| 21 | 15627413290 |
| 22 | 25112609019 |
| 23 | 39484650296 |
| 24 | 60859027054 |
| 25 | 92114682749 |
| 26 | 137111560949 |
| 27 | 200972392655 |