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) |
|---|---|
| 3 | 1 |
| 4 | 2 |
| 5 | 8 |
| 6 | 22 |
| 7 | 74 |
| 8 | 208 |
| 9 | 598 |
| 10 | 1600 |
| 11 | 4248 |
| 12 | 10880 |
| 13 | 27512 |
| 14 | 68096 |
| 15 | 166528 |
| 16 | 401408 |
| 17 | 957728 |
| 18 | 2260992 |
| 19 | 5292672 |
| 20 | 12288000 |
| 21 | 28329344 |
| 22 | 64880640 |
| 23 | 147721216 |
| 24 | 334495744 |
| 25 | 753670656 |
| 26 | 1690304512 |
| 27 | 3774887936 |
| 28 | 8396996608 |
| 29 | 18610157568 |
| 30 | 41104179200 |