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) |
|---|---|
| 2 | 12 |
| 3 | 198 |
| 4 | 4608 |
| 5 | 53730 |
| 6 | 378252 |
| 7 | 1909236 |
| 8 | 7628544 |
| 9 | 25628076 |
| 10 | 75297420 |
| 11 | 198807114 |
| 12 | 481029120 |
| 13 | 1082267550 |
| 14 | 2289691404 |
| 15 | 4595197320 |
| 16 | 8809614336 |
| 17 | 16225724664 |
| 18 | 28845544716 |
| 19 | 49690719342 |
| 20 | 83218759680 |
| 21 | 135872231418 |
| 22 | 216792905868 |
| 23 | 338738351292 |
| 24 | 519244496640 |
| 25 | 782084374500 |