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 | 0 |
| 1 | 7 |
| 2 | 98 |
| 3 | 1029 |
| 4 | 9604 |
| 5 | 84035 |
| 6 | 705894 |
| 7 | 5764801 |
| 8 | 46118408 |
| 9 | 363182463 |
| 10 | 2824752490 |
| 11 | 21750594173 |
| 12 | 166095446412 |
| 13 | 1259557135291 |
| 14 | 9495123019886 |
| 15 | 71213422649145 |
| 16 | 531726889113616 |
| 17 | 3954718737782519 |
| 18 | 29311444762388082 |
| 19 | 216579008522089717 |
| 20 | 1595845325952240020 |
| 21 | 11729463145748964147 |