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 | 8 |
| 4 | 86 |
| 5 | 1394 |
| 6 | 32134 |
| 7 | 957332 |
| 8 | 35154340 |
| 9 | 1537408202 |
| 10 | 78132541528 |
| 11 | 4528684996756 |
| 12 | 295011186006282 |
| 13 | 21345627856836734 |
| 14 | 1698954263159544138 |
| 15 | 147553846727480002824 |
| 16 | 13888244935445960871352 |
| 17 | 1408407905312396429259944 |
| 18 | 153105374581396386625831530 |