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 | 0 |
| 2 | 2 |
| 3 | 4 |
| 4 | 6 |
| 5 | 8 |
| 6 | 20 |
| 7 | 40 |
| 8 | 42 |
| 9 | 60 |
| 10 | 62 |
| 11 | 64 |
| 12 | 80 |
| 13 | 82 |
| 14 | 84 |
| 15 | 86 |
| 16 | 420 |
| 17 | 620 |
| 18 | 640 |
| 19 | 642 |
| 20 | 820 |
| 21 | 840 |
| 22 | 842 |
| 23 | 860 |
| 24 | 862 |
| 25 | 864 |
| 26 | 6420 |
| 27 | 8420 |
| 28 | 8620 |
| 29 | 8640 |
| 30 | 8642 |
| 31 | 86420 |