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 | 3 |
| 1 | 3 |
| 2 | 5 |
| 3 | 13 |
| 4 | 73 |
| 5 | 241 |
| 6 | 2161 |
| 7 | 15121 |
| 8 | 282241 |
| 9 | 1088641 |
| 10 | 10886401 |
| 11 | 199584001 |
| 12 | 958003201 |
| 13 | 18681062401 |
| 14 | 1133317785601 |
| 15 | 9153720576001 |
| 16 | 648606486528001 |
| 17 | 1778437140480001 |
| 18 | 12804747411456001 |
| 19 | 851515702861824001 |
| 20 | 41359334139002880001 |
| 21 | 3423093125504532480001 |
| 22 | 46084029838881914880001 |