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 | 0 |
| 2 | 0 |
| 3 | 165 |
| 4 | 495 |
| 5 | 10296 |
| 6 | 108108 |
| 7 | 1473615 |
| 8 | 20913750 |
| 9 | 321086480 |
| 10 | 5263562304 |
| 11 | 91807414686 |
| 12 | 1696802925090 |
| 13 | 33116968654560 |
| 14 | 680485905122760 |
| 15 | 14681498118551154 |
| 16 | 331788224215573983 |
| 17 | 7837028408940548400 |