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 | 0 |
| 2 | 6 |
| 3 | 27 |
| 4 | 216 |
| 5 | 2025 |
| 6 | 21708 |
| 7 | 260253 |
| 8 | 3460320 |
| 9 | 50395041 |
| 10 | 795324420 |
| 11 | 13495904829 |
| 12 | 244747554912 |
| 13 | 4718754452529 |
| 14 | 96285948702804 |
| 15 | 2071265238290565 |
| 16 | 46815054101658432 |
| 17 | 1108489016781839169 |
| 18 | 27424412680091114628 |
| 19 | 707277138662880504045 |
| 20 | 18974871706141125008640 |