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 | 4 |
| 1 | 32 |
| 2 | 474 |
| 3 | 4550 |
| 4 | 38688 |
| 5 | 314160 |
| 6 | 5890500 |
| 7 | 47154384 |
| 8 | 627314688 |
| 9 | 4227938208 |
| 10 | 44474529792 |
| 11 | 471238898040 |
| 12 | 3384209127992 |
| 13 | 31609375538016 |
| 14 | 321468276096000 |
| 15 | 3397292023738536 |
| 16 | 63981878014882800 |
| 17 | 314159266666564480 |
| 18 | 6855058424082419712 |
| 19 | 61964634989789392896 |