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) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 3 |
| 4 | 12 |
| 5 | 45 |
| 6 | 126 |
| 7 | 343 |
| 8 | 848 |
| 9 | 2034 |
| 10 | 4700 |
| 11 | 10648 |
| 12 | 23652 |
| 13 | 51935 |
| 14 | 112798 |
| 15 | 243120 |
| 16 | 520592 |
| 17 | 1109063 |
| 18 | 2352366 |
| 19 | 4971426 |
| 20 | 10473220 |
| 21 | 22003464 |
| 22 | 46115300 |
| 23 | 96440127 |
| 24 | 201288792 |
| 25 | 419381450 |
| 26 | 872351896 |
| 27 | 1811858058 |
| 28 | 3757992280 |
| 29 | 7784495839 |
| 30 | 16105959240 |
| 31 | 33285784442 |