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 | 1 |
| 2 | 13 |
| 3 | 229 |
| 4 | 4921 |
| 5 | 128841 |
| 6 | 4022341 |
| 7 | 146450893 |
| 8 | 6103787761 |
| 9 | 286833509137 |
| 10 | 15011892880381 |
| 11 | 866190689012661 |
| 12 | 54637591044108073 |
| 13 | 3740820141248285785 |
| 14 | 276304073198956644661 |
| 15 | 21900911192388373534621 |