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 | 47 |
| 2 | 2162 |
| 3 | 99452 |
| 4 | 4574792 |
| 5 | 210440432 |
| 6 | 9680259872 |
| 7 | 445291954112 |
| 8 | 20483429889152 |
| 9 | 942237774900992 |
| 10 | 43342937645445632 |
| 11 | 1993775131690499072 |
| 12 | 91713656057762957312 |
| 13 | 4218828178657096036352 |
| 14 | 194066096218226417672192 |
| 15 | 8927040426038415212920832 |