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 | 2 |
| 3 | 5 |
| 4 | 10 |
| 5 | 30 |
| 6 | 130 |
| 7 | 390 |
| 8 | 2730 |
| 9 | 13260 |
| 10 | 64090 |
| 11 | 192270 |
| 12 | 1345890 |
| 13 | 7113990 |
| 14 | 49797930 |
| 15 | 291673590 |
| 16 | 2041715130 |