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) |
|---|---|
| 1 | 7 |
| 2 | 49 |
| 3 | 211 |
| 4 | 1153 |
| 5 | 6139 |
| 6 | 31529 |
| 7 | 165783 |
| 8 | 867545 |
| 9 | 4529439 |
| 10 | 23698777 |
| 11 | 123917699 |
| 12 | 647878921 |
| 13 | 3387923179 |
| 14 | 17715041713 |
| 15 | 92629806615 |
| 16 | 484357042545 |
| 17 | 2532662234303 |
| 18 | 13243089222385 |
| 19 | 69247131747475 |
| 20 | 362087861614577 |
| 21 | 1893329530949883 |