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) |
|---|---|
| 4 | 1 |
| 5 | 9 |
| 6 | 51 |
| 7 | 209 |
| 8 | 696 |
| 9 | 1980 |
| 10 | 5000 |
| 11 | 11475 |
| 12 | 24375 |
| 13 | 48545 |
| 14 | 91581 |
| 15 | 164934 |
| 16 | 285376 |
| 17 | 476784 |
| 18 | 772416 |
| 19 | 1217610 |
| 20 | 1873125 |
| 21 | 2819025 |
| 22 | 4159375 |
| 23 | 6027615 |
| 24 | 8592936 |
| 25 | 12067484 |
| 26 | 16714776 |
| 27 | 22859109 |
| 28 | 30896411 |
| 29 | 41306265 |
| 30 | 54665625 |
| 31 | 71663900 |