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 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 42 |
| 6 | 176 |
| 7 | 792 |
| 8 | 3718 |
| 9 | 17977 |
| 10 | 89134 |
| 11 | 451276 |
| 12 | 2323520 |
| 13 | 12132164 |
| 14 | 64112359 |
| 15 | 342325709 |
| 16 | 1844349560 |
| 17 | 10015581680 |
| 18 | 54770336324 |
| 19 | 301384802048 |
| 20 | 1667727404093 |
| 21 | 9275102575355 |
| 22 | 51820051838712 |
| 23 | 290726957916112 |
| 24 | 1637293969337171 |
| 25 | 9253082936723602 |