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 | 2 |
| 2 | 42 |
| 3 | 90 |
| 4 | 210 |
| 5 | 630 |
| 6 | 1050 |
| 7 | 1470 |
| 8 | 2310 |
| 9 | 6930 |
| 10 | 16170 |
| 11 | 30030 |
| 12 | 90090 |
| 13 | 150150 |
| 14 | 210210 |
| 15 | 570570 |
| 16 | 690690 |
| 17 | 870870 |
| 18 | 2072070 |
| 19 | 3573570 |
| 20 | 3993990 |
| 21 | 4834830 |