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 | 3 |
| 1 | 12 |
| 2 | 56 |
| 3 | 288 |
| 4 | 1568 |
| 5 | 8832 |
| 6 | 50816 |
| 7 | 296448 |
| 8 | 1745408 |
| 9 | 10340352 |
| 10 | 61515776 |
| 11 | 366993408 |
| 12 | 2193563648 |
| 13 | 13127811072 |
| 14 | 78632615936 |
| 15 | 471258759168 |
| 16 | 2825404940288 |
| 17 | 16943839444992 |
| 18 | 101628676407296 |
| 19 | 609634618441728 |