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 | 1 |
| 3 | 8 |
| 4 | 77 |
| 5 | 824 |
| 6 | 9448 |
| 7 | 113728 |
| 8 | 1419349 |
| 9 | 18215576 |
| 10 | 239034104 |
| 11 | 3194168768 |
| 12 | 43331889928 |
| 13 | 595375647424 |
| 14 | 8270102936896 |
| 15 | 115966112244224 |
| 16 | 1639592525879333 |
| 17 | 23350785267093848 |
| 18 | 334714889445506584 |
| 19 | 4825695011761675456 |
| 20 | 69936530485677013528 |