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) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 12 |
| 4 | 36 |
| 5 | 160 |
| 6 | 810 |
| 7 | 5376 |
| 8 | 41160 |
| 9 | 366336 |
| 10 | 3638250 |
| 11 | 39959040 |
| 12 | 479126340 |
| 13 | 6227619840 |
| 14 | 87180183090 |
| 15 | 1307684044800 |
| 16 | 20922822320400 |
| 17 | 355687603568640 |
| 18 | 6402374325997650 |
| 19 | 121645103938928640 |
| 20 | 2432902021271221500 |
| 21 | 51090942249743155200 |
| 22 | 1124000728080092512650 |