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 | 2 |
| 2 | 1 |
| 3 | 2 |
| 4 | 0 |
| 5 | 0 |
| 6 | 8 |
| 7 | 0 |
| 8 | 80 |
| 9 | 728 |
| 10 | 224 |
| 11 | 323 |
| 12 | 39168 |
| 13 | 82943 |
| 14 | 176399 |
| 15 | 215295 |
| 16 | 3444735 |
| 17 | 26167683 |
| 18 | 114349224 |
| 19 | 255004928 |
| 20 | 1158920360 |
| 21 | 11638526760 |
| 22 | 42128246888 |
| 23 | 191052974115 |
| 24 | 97216010328 |
| 25 | 2430400258224 |
| 26 | 1553580508515 |
| 27 | 4666092737475 |