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 | 17 |
| 2 | 209 |
| 3 | 2273 |
| 4 | 23201 |
| 5 | 228017 |
| 6 | 2186609 |
| 7 | 20620673 |
| 8 | 192174401 |
| 9 | 1775688017 |
| 10 | 16304021009 |
| 11 | 148995991073 |
| 12 | 1356782533601 |
| 13 | 12321773100017 |
| 14 | 111671069983409 |
| 15 | 1010465414433473 |
| 16 | 9132169221980801 |
| 17 | 82455386442384017 |
| 18 | 743959522093353809 |
| 19 | 6708663007623467873 |
| 20 | 60469158230094196001 |