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 | 1 |
| 2 | 3 |
| 3 | 20 |
| 4 | 225 |
| 5 | 3789 |
| 6 | 89341 |
| 7 | 2821552 |
| 8 | 115377921 |
| 9 | 5939637425 |
| 10 | 375840753541 |
| 11 | 28641787322796 |
| 12 | 2583828842108449 |
| 13 | 271949027324094925 |
| 14 | 32986652806128680205 |
| 15 | 4563200871898056653504 |
| 16 | 713455071424061222336513 |