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 | 1 |
| 2 | 3 |
| 3 | 4 |
| 4 | 16 |
| 5 | 36 |
| 6 | 64 |
| 7 | 218 |
| 8 | 1104 |
| 9 | 2112 |
| 10 | 4096 |
| 11 | 9608 |
| 12 | 90416 |
| 13 | 266496 |
| 14 | 528384 |
| 15 | 1048576 |
| 16 | 1540944 |
| 17 | 30194176 |
| 18 | 135032832 |
| 19 | 269500416 |
| 20 | 537919488 |
| 21 | 1073741824 |