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 | 0 |
| 2 | 0 |
| 3 | 8 |
| 4 | 32 |
| 5 | 152 |
| 6 | 512 |
| 7 | 1880 |
| 8 | 5920 |
| 9 | 19464 |
| 10 | 59168 |
| 11 | 183776 |
| 12 | 545392 |
| 13 | 1638400 |
| 14 | 4778000 |
| 15 | 14043224 |
| 16 | 40422544 |
| 17 | 116977176 |
| 18 | 333346928 |
| 19 | 953538440 |
| 20 | 2695689520 |
| 21 | 7642091352 |
| 22 | 21464794032 |
| 23 | 60417010152 |
| 24 | 168787016352 |
| 25 | 472315518008 |
| 26 | 1313548558528 |
| 27 | 3657850909680 |
| 28 | 10133559518800 |