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 | 2 |
| 3 | 7 |
| 4 | 32 |
| 5 | 168 |
| 6 | 970 |
| 7 | 5984 |
| 8 | 38786 |
| 9 | 261160 |
| 10 | 1812630 |
| 11 | 12895360 |
| 12 | 93638634 |
| 13 | 691793872 |
| 14 | 5186869122 |
| 15 | 39388514522 |
| 16 | 302457399674 |
| 17 | 2345362579172 |
| 18 | 18345337742960 |
| 19 | 144612959167806 |
| 20 | 1147920496989270 |
| 21 | 9169516892088470 |