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 | 5 |
| 3 | 16 |
| 4 | 60 |
| 5 | 156 |
| 6 | 540 |
| 7 | 1296 |
| 8 | 4320 |
| 9 | 9936 |
| 10 | 32400 |
| 11 | 72576 |
| 12 | 233280 |
| 13 | 513216 |
| 14 | 1632960 |
| 15 | 3545856 |
| 16 | 11197440 |
| 17 | 24074496 |
| 18 | 75582720 |
| 19 | 161243136 |
| 20 | 503884800 |
| 21 | 1068235776 |
| 22 | 3325639680 |
| 23 | 7014076416 |
| 24 | 21767823360 |
| 25 | 45712429056 |
| 26 | 141490851840 |