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 | 18 |
| 3 | 172 |
| 4 | 2295 |
| 5 | 40043 |
| 6 | 875936 |
| 7 | 23308546 |
| 8 | 737478487 |
| 9 | 27252363585 |
| 10 | 1159335917625 |
| 11 | 56103737161197 |
| 12 | 3057787510932485 |
| 13 | 186102920689311261 |
| 14 | 12555513437042340449 |
| 15 | 932964243520888524391 |
| 16 | 75926403820972271325522 |
| 17 | 6733532223196893844825456 |
| 18 | 647846856775383975668238328 |
| 19 | 67349524752043243630964385000 |