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 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 27 |
| 4 | 256 |
| 5 | 3120 |
| 6 | 46470 |
| 7 | 817950 |
| 8 | 16612120 |
| 9 | 382367160 |
| 10 | 9836517600 |
| 11 | 279684716850 |
| 12 | 8709747354000 |
| 13 | 294818964039600 |
| 14 | 10777792243818600 |
| 15 | 423193629950091000 |
| 16 | 17762853608696196000 |
| 17 | 793668469023770340000 |
| 18 | 37611450798744238416000 |
| 19 | 1884235285123539720372000 |