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 | 1 |
| 2 | 5 |
| 3 | 31 |
| 4 | 249 |
| 5 | 2491 |
| 6 | 29893 |
| 7 | 418503 |
| 8 | 6696049 |
| 9 | 120528883 |
| 10 | 2410577661 |
| 11 | 53032708543 |
| 12 | 1272785005033 |
| 13 | 33092410130859 |
| 14 | 926587483664053 |
| 15 | 27797624509921591 |
| 16 | 889523984317490913 |
| 17 | 30243815466794691043 |