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 | 1 |
| 2 | 2 |
| 3 | 15 |
| 4 | 52 |
| 5 | 5 |
| 6 | 4140 |
| 7 | 203 |
| 8 | 0 |
| 9 | 4140 |
| 10 | 4140 |
| 11 | 10293358946226376485095653 |
| 12 | 4140 |
| 13 | 52 |
| 14 | 51724158235372 |
| 15 | 15 |
| 16 | 0 |
| 17 | 4506715738447323 |
| 18 | 4140 |
| 19 | 21147 |
| 20 | 4140 |
| 21 | 21147 |
| 22 | 1052928518014714166107781298021583534928402714242132 |
| 23 | 4140 |
| 24 | 0 |
| 25 | 115975 |
| 26 | 52 |
| 27 | 82864869804 |
| 28 | 51724158235372 |
| 29 | 203 |
| 30 | 4140 |