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 | 27 |
| 3 | 143 |
| 4 | 3315 |
| 5 | 20349 |
| 6 | 260015 |
| 7 | 1710855 |
| 8 | 92116035 |
| 9 | 631165425 |
| 10 | 8775943605 |
| 11 | 61750730457 |
| 12 | 1755702867191 |
| 13 | 12587970424449 |
| 14 | 181858466731095 |
| 15 | 1322239639929719 |
| 16 | 154702037871777123 |
| 17 | 1137023085979691001 |
| 18 | 16789716964765636633 |