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 | 14 |
| 3 | 98 |
| 4 | 726 |
| 5 | 5512 |
| 6 | 42614 |
| 7 | 333608 |
| 8 | 2636326 |
| 9 | 20985272 |
| 10 | 168012824 |
| 11 | 1351507830 |
| 12 | 10914317934 |
| 13 | 88432329546 |
| 14 | 718545161208 |
| 15 | 5852747363518 |
| 16 | 47774241056710 |
| 17 | 390702055798978 |
| 18 | 3200542803221192 |
| 19 | 26257321971526646 |
| 20 | 215705170816632376 |
| 21 | 1774181109262878848 |