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 | 1 |
| 2 | 12 |
| 3 | 228 |
| 4 | 5928 |
| 5 | 195624 |
| 6 | 7824960 |
| 7 | 367773120 |
| 8 | 19859748480 |
| 9 | 1211444657280 |
| 10 | 82378236695040 |
| 11 | 6178367752128000 |
| 12 | 506626155674496000 |
| 13 | 45089727855030144000 |
| 14 | 4328613874082893824000 |
| 15 | 445847229030538063872000 |
| 16 | 49043195193359187025920000 |
| 17 | 5738053837623024882032640000 |