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 | 7 |
| 2 | 62 |
| 3 | 654 |
| 4 | 7944 |
| 5 | 108696 |
| 6 | 1649232 |
| 7 | 27422352 |
| 8 | 495057024 |
| 9 | 9631281024 |
| 10 | 200682406656 |
| 11 | 4455296877312 |
| 12 | 104921038236672 |
| 13 | 2610989435003904 |
| 14 | 68430995893131264 |
| 15 | 1883330926998829056 |
| 16 | 54286270223002140672 |
| 17 | 1635031821385383247872 |
| 18 | 51347572582353094508544 |