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 | 4 |
| 3 | 10 |
| 4 | 32 |
| 5 | 130 |
| 6 | 652 |
| 7 | 3914 |
| 8 | 27400 |
| 9 | 219202 |
| 10 | 1972820 |
| 11 | 19728202 |
| 12 | 217010224 |
| 13 | 2604122690 |
| 14 | 33853594972 |
| 15 | 473950329610 |
| 16 | 7109254944152 |
| 17 | 113748079106434 |
| 18 | 1933717344809380 |
| 19 | 34806912206568842 |
| 20 | 661331331924808000 |
| 21 | 13226626638496160002 |
| 22 | 277759159408419360044 |