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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 15 |
| 8 | 1 |
| 9 | 10 |
| 10 | 50 |
| 11 | 73 |
| 12 | 3564 |
| 13 | 2917 |
| 14 | 65875 |
| 15 | 329375 |
| 16 | 1071361 |
| 17 | 1095123 |
| 18 | 37035577 |
| 19 | 239275125 |
| 20 | 1196735625 |
| 21 | 9366854761 |
| 22 | 15974824888 |
| 23 | 327898783057 |
| 24 | 822231218750 |
| 25 | 4324684843750 |
| 26 | 75814982916082 |
| 27 | 650698890882335 |
| 28 | 2788223698649662 |
| 29 | 10374046091875000 |
| 30 | 91400348409375000 |