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 | 7 |
| 2 | 42 |
| 3 | 252 |
| 4 | 1470 |
| 5 | 8610 |
| 6 | 50190 |
| 7 | 292740 |
| 8 | 1706250 |
| 9 | 9946020 |
| 10 | 57970080 |
| 11 | 337883700 |
| 12 | 1969343880 |
| 13 | 11478292770 |
| 14 | 66900843240 |
| 15 | 389929523550 |
| 16 | 2272690998690 |