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) |
|---|---|
| 4 | 2 |
| 5 | 8 |
| 6 | 26 |
| 7 | 80 |
| 8 | 224 |
| 9 | 596 |
| 10 | 1536 |
| 11 | 3840 |
| 12 | 9384 |
| 13 | 22528 |
| 14 | 53248 |
| 15 | 124240 |
| 16 | 286720 |
| 17 | 655360 |
| 18 | 1485472 |
| 19 | 3342336 |
| 20 | 7471104 |
| 21 | 16602432 |
| 22 | 36700160 |
| 23 | 80740352 |
| 24 | 176859776 |
| 25 | 385875968 |
| 26 | 838860800 |
| 27 | 1817531648 |
| 28 | 3925868544 |
| 29 | 8455716864 |
| 30 | 18164132352 |
| 31 | 38923141120 |