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 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 22 |
| 5 | 88 |
| 6 | 374 |
| 7 | 1668 |
| 8 | 7744 |
| 9 | 37182 |
| 10 | 183666 |
| 11 | 929480 |
| 12 | 4803018 |
| 13 | 25274088 |
| 14 | 135132886 |
| 15 | 732779504 |
| 16 | 4023875702 |
| 17 | 22346542912 |
| 18 | 125368768090 |
| 19 | 709852110576 |
| 20 | 4053103780006 |
| 21 | 23320440656376 |
| 22 | 135126739754922 |
| 23 | 788061492048436 |
| 24 | 4623591001082002 |
| 25 | 27277772831911348 |