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 | 2 |
| 1 | 11 |
| 2 | 69 |
| 3 | 449 |
| 4 | 2961 |
| 5 | 19721 |
| 6 | 132609 |
| 7 | 899609 |
| 8 | 6149121 |
| 9 | 42287561 |
| 10 | 292182849 |
| 11 | 2025979769 |
| 12 | 14084900481 |
| 13 | 98108127401 |
| 14 | 684321821889 |
| 15 | 4778064771929 |
| 16 | 33385475479041 |
| 17 | 233393324431241 |
| 18 | 1632227908017729 |
| 19 | 11417967509964089 |
| 20 | 79887630243516801 |
| 21 | 559022690783231081 |
| 22 | 3912205202997138369 |