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 | 12 |
| 2 | 228 |
| 3 | 4020 |
| 4 | 65040 |
| 5 | 1047540 |
| 6 | 16768860 |
| 7 | 268419060 |
| 8 | 4294836480 |
| 9 | 68719210560 |
| 10 | 1099509531420 |
| 11 | 17592181850100 |
| 12 | 281474943095280 |
| 13 | 4503599560261620 |
| 14 | 72057593501073180 |
| 15 | 1152921503532053580 |
| 16 | 18446744065119682560 |
| 17 | 295147905162172956660 |
| 18 | 4722366482732189753280 |