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 | 63 |
| 2 | 3905 |
| 3 | 242047 |
| 4 | 15003009 |
| 5 | 929944511 |
| 6 | 57641556673 |
| 7 | 3572846569215 |
| 8 | 221458845734657 |
| 9 | 13726875588979519 |
| 10 | 850844827670995521 |
| 11 | 52738652440012742783 |
| 12 | 3268945606453119057025 |
| 13 | 202621888947653368792767 |
| 14 | 12559288169148055746094529 |
| 15 | 778473244598231802889068031 |