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 | 3 |
| 2 | 15 |
| 3 | 126 |
| 4 | 1395 |
| 5 | 18678 |
| 6 | 289926 |
| 7 | 5090220 |
| 8 | 99466371 |
| 9 | 2138575590 |
| 10 | 50153137650 |
| 11 | 1274013771300 |
| 12 | 34853264146350 |
| 13 | 1021795130252988 |
| 14 | 31964591332833900 |
| 15 | 1062945070050997656 |
| 16 | 37447053359058465507 |
| 17 | 1393372283171378001030 |