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 | 1 |
| 2 | 3 |
| 3 | 16 |
| 4 | 145 |
| 5 | 2111 |
| 6 | 47624 |
| 7 | 1626003 |
| 8 | 82564031 |
| 9 | 6146805142 |
| 10 | 662718022355 |
| 11 | 102336213875523 |
| 12 | 22408881211102698 |
| 13 | 6895949927379360277 |
| 14 | 2958271314760111914191 |
| 15 | 1756322140048351303019576 |