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 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 25 |
| 5 | 91 |
| 6 | 444 |
| 7 | 2920 |
| 8 | 25996 |
| 9 | 314752 |
| 10 | 5201874 |
| 11 | 117719942 |
| 12 | 3658433597 |
| 13 | 156505343943 |
| 14 | 9234365056453 |
| 15 | 752841451059559 |
| 16 | 84938741035295776 |
| 17 | 13279814559055121447 |
| 18 | 2880581923860441220144 |
| 19 | 867855593621657824023139 |