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) |
|---|---|
| 2 | 10 |
| 3 | 34 |
| 4 | 136 |
| 5 | 520 |
| 6 | 2080 |
| 7 | 8224 |
| 8 | 32896 |
| 9 | 131200 |
| 10 | 524800 |
| 11 | 2097664 |
| 12 | 8390656 |
| 13 | 33556480 |
| 14 | 134225920 |
| 15 | 536879104 |
| 16 | 2147516416 |
| 17 | 8589967360 |
| 18 | 34359869440 |
| 19 | 137439084544 |
| 20 | 549756338176 |
| 21 | 2199023779840 |
| 22 | 8796095119360 |