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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 16 |
| 7 | 20 |
| 8 | 128 |
| 9 | 396 |
| 10 | 2288 |
| 11 | 11152 |
| 12 | 65712 |
| 13 | 437848 |
| 14 | 3118664 |
| 15 | 23387448 |
| 16 | 183463680 |
| 17 | 1474699536 |
| 18 | 12485203304 |
| 19 | 110956890352 |
| 20 | 1028589512656 |
| 21 | 9801351322432 |
| 22 | 97731300891440 |
| 23 | 1014610719838792 |