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 | 3 |
| 3 | 19 |
| 4 | 201 |
| 5 | 3081 |
| 6 | 62663 |
| 7 | 1598185 |
| 8 | 49158651 |
| 9 | 1772832643 |
| 10 | 73394322615 |
| 11 | 3431751900897 |
| 12 | 178904412061235 |
| 13 | 10290301519034057 |
| 14 | 647401635395456919 |
| 15 | 44227879174393279133 |