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 | 6 |
| 3 | 84 |
| 4 | 1820 |
| 5 | 53130 |
| 6 | 1947792 |
| 7 | 85900584 |
| 8 | 4426165368 |
| 9 | 260887834350 |
| 10 | 17310309456440 |
| 11 | 1276749965026536 |
| 12 | 103619293824707388 |
| 13 | 9176358300744339432 |
| 14 | 880530516383349192480 |
| 15 | 91005567811177478095440 |
| 16 | 10078751602022313874633200 |
| 17 | 1190739044344491048895397910 |