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) |
|---|---|
| 7 | 1 |
| 8 | 7 |
| 9 | 56 |
| 10 | 420 |
| 11 | 3360 |
| 12 | 28182 |
| 13 | 250404 |
| 14 | 2354352 |
| 15 | 23408385 |
| 16 | 245710465 |
| 17 | 2717803088 |
| 18 | 31615680096 |
| 19 | 386038045848 |
| 20 | 4938320959740 |
| 21 | 66064056802800 |
| 22 | 922665034672080 |
| 23 | 13431181585022355 |
| 24 | 203477178533784540 |
| 25 | 3203526845947149260 |
| 26 | 52344335808818684400 |
| 27 | 886527902050136045700 |