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 | 2 |
| 2 | 3 |
| 3 | 6 |
| 4 | 14 |
| 5 | 42 |
| 6 | 158 |
| 7 | 756 |
| 8 | 4594 |
| 9 | 35532 |
| 10 | 349428 |
| 11 | 4370436 |
| 12 | 69532964 |
| 13 | 1407280392 |
| 14 | 36228710348 |
| 15 | 1186337370456 |
| 16 | 49415178236344 |
| 17 | 2618246576596392 |
| 18 | 176462813970065208 |
| 19 | 15128228719573952976 |
| 20 | 1649746715671916095304 |