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 | 1 |
| 2 | 5 |
| 3 | 29 |
| 4 | 201 |
| 5 | 1657 |
| 6 | 15821 |
| 7 | 170389 |
| 8 | 2032785 |
| 9 | 26546673 |
| 10 | 376085653 |
| 11 | 5736591885 |
| 12 | 93614616409 |
| 13 | 1625661357673 |
| 14 | 29905322979421 |
| 15 | 580513190237573 |
| 16 | 11850869542405409 |
| 17 | 253669139947767777 |
| 18 | 5678266212792053029 |
| 19 | 132607996474971041789 |
| 20 | 3224106929536557918697 |