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 | 3 |
| 1 | 5 |
| 2 | 13 |
| 3 | 45 |
| 4 | 173 |
| 5 | 685 |
| 6 | 2733 |
| 7 | 10925 |
| 8 | 43693 |
| 9 | 174765 |
| 10 | 699053 |
| 11 | 2796205 |
| 12 | 11184813 |
| 13 | 44739245 |
| 14 | 178956973 |
| 15 | 715827885 |
| 16 | 2863311533 |
| 17 | 11453246125 |
| 18 | 45812984493 |
| 19 | 183251937965 |
| 20 | 733007751853 |
| 21 | 2932031007405 |
| 22 | 11728124029613 |
| 23 | 46912496118445 |
| 24 | 187649984473773 |
| 25 | 750599937895085 |
| 26 | 3002399751580333 |