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 | 5 |
| 2 | 70 |
| 3 | 1470 |
| 4 | 38808 |
| 5 | 1189188 |
| 6 | 40489020 |
| 7 | 1491345570 |
| 8 | 58388438680 |
| 9 | 2400295633736 |
| 10 | 102692368441936 |
| 11 | 4542162450316400 |
| 12 | 206643434552856000 |
| 13 | 9631060074695610000 |
| 14 | 458381806260954003000 |
| 15 | 22220282755463598704250 |
| 16 | 1094733022441519300455000 |
| 17 | 54717445279576990999935000 |