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 | 0 |
| 1 | 1 |
| 2 | 1448 |
| 3 | 102275 |
| 4 | 2097152 |
| 5 | 21836601 |
| 6 | 148111277 |
| 7 | 747359260 |
| 8 | 3037000499 |
| 9 | 10460353203 |
| 10 | 31622776601 |
| 11 | 86024705429 |
| 12 | 214488041413 |
| 13 | 497055861119 |
| 14 | 1082291816449 |
| 15 | 2233357359474 |
| 16 | 4398046511104 |
| 17 | 8312155792152 |
| 18 | 15148209527700 |
| 19 | 26724698233906 |