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) |
|---|---|
| 1 | 6 |
| 2 | 97 |
| 3 | 1028 |
| 4 | 9603 |
| 5 | 84034 |
| 6 | 705893 |
| 7 | 5764800 |
| 8 | 46118407 |
| 9 | 363182462 |
| 10 | 2824752489 |
| 11 | 21750594172 |
| 12 | 166095446411 |
| 13 | 1259557135290 |
| 14 | 9495123019885 |
| 15 | 71213422649144 |
| 16 | 531726889113615 |
| 17 | 3954718737782518 |
| 18 | 29311444762388081 |
| 19 | 216579008522089716 |
| 20 | 1595845325952240019 |
| 21 | 11729463145748964146 |