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 | 0 |
| 4 | 0 |
| 5 | 32 |
| 6 | 352 |
| 7 | 3072 |
| 8 | 30848 |
| 9 | 295456 |
| 10 | 2896832 |
| 11 | 28120096 |
| 12 | 273895232 |
| 13 | 2664515712 |
| 14 | 25931157504 |
| 15 | 252338724352 |
| 16 | 2455552258304 |
| 17 | 23895692937216 |
| 18 | 232533011307776 |
| 19 | 2262837745837568 |
| 20 | 22020130538878208 |
| 21 | 214282979451801088 |
| 22 | 2085233793265765376 |
| 23 | 20291876152214982656 |