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) |
|---|---|
| 1 | 3 |
| 2 | 5 |
| 3 | 13 |
| 4 | 61 |
| 5 | 421 |
| 6 | 3361 |
| 7 | 30241 |
| 8 | 332641 |
| 9 | 3991681 |
| 10 | 55883521 |
| 11 | 950019841 |
| 12 | 19000396801 |
| 13 | 456009523201 |
| 14 | 13680285696001 |
| 15 | 465129713664001 |
| 16 | 20465707401216001 |
| 17 | 1473530932887552001 |
| 18 | 125250129295441920001 |
| 19 | 10771511119408005120001 |