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 | 4 |
| 4 | 9 |
| 5 | 22 |
| 6 | 56 |
| 7 | 147 |
| 8 | 388 |
| 9 | 1047 |
| 10 | 2806 |
| 11 | 7600 |
| 12 | 20437 |
| 13 | 55313 |
| 14 | 148752 |
| 15 | 401629 |
| 16 | 1078746 |
| 17 | 2905751 |
| 18 | 7793632 |
| 19 | 20949045 |
| 20 | 56112530 |
| 21 | 150561752 |
| 22 | 402802376 |
| 23 | 1079193821 |
| 24 | 2884195424 |
| 25 | 7717665979 |
| 26 | 20607171273 |
| 27 | 55082560423 |
| 28 | 146961482787 |
| 29 | 392462843329 |
| 30 | 1046373230168 |
| 31 | 2792115083878 |