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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 32 |
| 6 | 300 |
| 7 | 1852 |
| 8 | 9576 |
| 9 | 45096 |
| 10 | 201060 |
| 11 | 866324 |
| 12 | 3650592 |
| 13 | 15154240 |
| 14 | 62260380 |
| 15 | 253939116 |
| 16 | 1030367448 |
| 17 | 4165106264 |
| 18 | 16790875860 |
| 19 | 67553807428 |
| 20 | 271383782544 |
| 21 | 1089035545968 |
| 22 | 4366631897100 |
| 23 | 17497971562460 |
| 24 | 70086163646280 |
| 25 | 280627369334152 |
| 26 | 1123357369925700 |