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 | 1 |
| 4 | 4 |
| 5 | 13 |
| 6 | 66 |
| 7 | 394 |
| 8 | 2759 |
| 9 | 22053 |
| 10 | 198481 |
| 11 | 1984746 |
| 12 | 21832207 |
| 13 | 261986098 |
| 14 | 3405819275 |
| 15 | 47681467093 |
| 16 | 715222006464 |
| 17 | 11443552081333 |
| 18 | 194540385382662 |
| 19 | 3501726936689833 |
| 20 | 66532811797106828 |
| 21 | 1330656235940151698 |
| 22 | 27943780954743188420 |
| 23 | 614763181004328313035 |
| 24 | 14139553163099551199806 |