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 | 25 |
| 2 | 340 |
| 3 | 1740 |
| 4 | 9016 |
| 5 | 44916 |
| 6 | 223788 |
| 7 | 1119424 |
| 8 | 5621396 |
| 9 | 28130560 |
| 10 | 140718764 |
| 11 | 704493864 |
| 12 | 3528165236 |
| 13 | 17658676752 |
| 14 | 88394841700 |
| 15 | 442557740144 |
| 16 | 2215472575772 |
| 17 | 11090095537400 |
| 18 | 55519269652292 |
| 19 | 277940545496176 |
| 20 | 1391364670745476 |