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 | 0 |
| 2 | 3 |
| 3 | 0 |
| 4 | 26 |
| 5 | 0 |
| 6 | 345 |
| 7 | 0 |
| 8 | 5754 |
| 9 | 0 |
| 10 | 110586 |
| 11 | 0 |
| 12 | 2341548 |
| 13 | 0 |
| 14 | 53208441 |
| 15 | 0 |
| 16 | 1276027610 |
| 17 | 0 |
| 18 | 31930139670 |
| 19 | 0 |
| 20 | 826963069140 |
| 21 | 0 |
| 22 | 22035414489270 |
| 23 | 0 |
| 24 | 601361536493340 |
| 25 | 0 |
| 26 | 16749316314679500 |
| 27 | 0 |
| 28 | 474777481850283240 |
| 29 | 0 |
| 30 | 13665774112508864385 |
| 31 | 0 |