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 | 165 |
| 4 | 2805 |
| 5 | 86955 |
| 6 | 3565155 |
| 7 | 210344145 |
| 8 | 14093057715 |
| 9 | 1169723790345 |
| 10 | 127499893147605 |
| 11 | 16192486429745835 |
| 12 | 2542220369470096095 |
| 13 | 455057446135147201005 |
| 14 | 86915972211813115391955 |
| 15 | 18339270136692567347702505 |
| 16 | 4419764102942908730796303705 |