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 | 10 |
| 4 | 55 |
| 5 | 250 |
| 6 | 1051 |
| 7 | 4270 |
| 8 | 17095 |
| 9 | 68050 |
| 10 | 270451 |
| 11 | 1075030 |
| 12 | 4276735 |
| 13 | 17030650 |
| 14 | 67881451 |
| 15 | 270777790 |
| 16 | 1080817975 |
| 17 | 4316294050 |
| 18 | 17244046051 |
| 19 | 68912400550 |
| 20 | 275457464815 |
| 21 | 1101251874250 |
| 22 | 4403270396251 |
| 23 | 17607863991310 |
| 24 | 70415790601255 |
| 25 | 281616141147250 |
| 26 | 1126323450484051 |