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 | 4 |
| 2 | 36 |
| 3 | 48 |
| 4 | 240 |
| 5 | 720 |
| 6 | 1680 |
| 7 | 15120 |
| 8 | 20160 |
| 9 | 45360 |
| 10 | 50400 |
| 11 | 221760 |
| 12 | 498960 |
| 13 | 554400 |
| 14 | 665280 |
| 15 | 2882880 |
| 16 | 6486480 |
| 17 | 14414400 |
| 18 | 17297280 |
| 19 | 32432400 |
| 20 | 43243200 |
| 21 | 110270160 |
| 22 | 245044800 |
| 23 | 294053760 |
| 24 | 735134400 |
| 25 | 2095133040 |
| 26 | 2205403200 |
| 27 | 4655851200 |