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 | 4 |
| 5 | 68 |
| 6 | 812 |
| 7 | 8512 |
| 8 | 84312 |
| 9 | 814184 |
| 10 | 7781712 |
| 11 | 74182124 |
| 12 | 708344640 |
| 13 | 6790655496 |
| 14 | 65440865012 |
| 15 | 634347822304 |
| 16 | 6186652422650 |
| 17 | 60707391493004 |
| 18 | 599283097168488 |
| 19 | 5950282272766412 |
| 20 | 59408426130151164 |
| 21 | 596269843123151304 |
| 22 | 6014472189177940224 |
| 23 | 60952019560703982452 |