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 | 6 |
| 1 | 55 |
| 2 | 447 |
| 3 | 3583 |
| 4 | 28671 |
| 5 | 229375 |
| 6 | 1835007 |
| 7 | 14680063 |
| 8 | 117440511 |
| 9 | 939524095 |
| 10 | 7516192767 |
| 11 | 60129542143 |
| 12 | 481036337151 |
| 13 | 3848290697215 |
| 14 | 30786325577727 |
| 15 | 246290604621823 |
| 16 | 1970324836974591 |
| 17 | 15762598695796735 |
| 18 | 126100789566373887 |