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 | 21 |
| 3 | 162 |
| 4 | 1365 |
| 5 | 12219 |
| 6 | 114156 |
| 7 | 1100649 |
| 8 | 10871175 |
| 9 | 109438830 |
| 10 | 1118798079 |
| 11 | 11583712617 |
| 12 | 121219182504 |
| 13 | 1280065637487 |
| 14 | 13623341795049 |
| 15 | 145977237305874 |
| 16 | 1573536198376401 |
| 17 | 17051418418204671 |
| 18 | 185646639499541892 |