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 | 337 |
| 4 | 2311 |
| 5 | 15816 |
| 6 | 108032 |
| 7 | 736525 |
| 8 | 5012171 |
| 9 | 34047931 |
| 10 | 230889543 |
| 11 | 1563104184 |
| 12 | 10564826628 |
| 13 | 71293105297 |
| 14 | 480355314513 |
| 15 | 3231663192859 |
| 16 | 21709801573961 |
| 17 | 145636117720769 |
| 18 | 975623832619371 |
| 19 | 6526972402359763 |
| 20 | 43608650962250889 |