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 | 0 |
| 2 | 1 |
| 3 | 5 |
| 4 | 22 |
| 5 | 210 |
| 6 | 287 |
| 7 | 782 |
| 8 | 1001 |
| 9 | 2882 |
| 10 | 7740 |
| 11 | 15251 |
| 12 | 77180 |
| 13 | 565187 |
| 14 | 720027 |
| 15 | 781565 |
| 16 | 7081807 |
| 17 | 7451547 |
| 18 | 26811862 |
| 19 | 54177145 |
| 20 | 206489067 |
| 21 | 246214610 |
| 22 | 760984602 |
| 23 | 1050660501 |
| 24 | 1085885801 |
| 25 | 1528888251 |
| 26 | 2642326276 |
| 27 | 2911771192 |
| 28 | 6726232462 |
| 29 | 24375132126 |
| 30 | 62123157342 |