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 | 10 |
| 1 | 37 |
| 2 | 145 |
| 3 | 577 |
| 4 | 2305 |
| 5 | 9217 |
| 6 | 36865 |
| 7 | 147457 |
| 8 | 589825 |
| 9 | 2359297 |
| 10 | 9437185 |
| 11 | 37748737 |
| 12 | 150994945 |
| 13 | 603979777 |
| 14 | 2415919105 |
| 15 | 9663676417 |
| 16 | 38654705665 |
| 17 | 154618822657 |
| 18 | 618475290625 |
| 19 | 2473901162497 |
| 20 | 9895604649985 |
| 21 | 39582418599937 |