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 | 3 |
| 3 | 31 |
| 4 | 115 |
| 5 | 3019 |
| 6 | 973 |
| 7 | 48877 |
| 8 | 191833 |
| 9 | 5257891 |
| 10 | 5194387 |
| 11 | 634871227 |
| 12 | 629535127 |
| 13 | 107159834863 |
| 14 | 106497287263 |
| 15 | 107074439839 |
| 16 | 426268707331 |
| 17 | 123711093737059 |
| 18 | 41082589491553 |
| 19 | 14880853934789833 |
| 20 | 2967138724292741 |
| 21 | 2975331071381381 |