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 | 3 |
| 2 | 15 |
| 3 | 218 |
| 4 | 7273 |
| 5 | 434654 |
| 6 | 40417797 |
| 7 | 5369210845 |
| 8 | 962496995941 |
| 9 | 223528473482380 |
| 10 | 65221305164439085 |
| 11 | 23343099723197369886 |
| 12 | 10052235133879615066675 |
| 13 | 5126300310101866339983229 |