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 | 11 |
| 3 | 137 |
| 4 | 363 |
| 5 | 7129 |
| 6 | 83711 |
| 7 | 1145993 |
| 8 | 1195757 |
| 9 | 42142223 |
| 10 | 275295799 |
| 11 | 18858053 |
| 12 | 444316699 |
| 13 | 34052522467 |
| 14 | 312536252003 |
| 15 | 9227046511387 |
| 16 | 290774257297357 |
| 17 | 53676090078349 |
| 18 | 54437269998109 |
| 19 | 2040798836801833 |
| 20 | 2066035355155033 |
| 21 | 85691034670497533 |