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 | 4 |
| 2 | 28 |
| 3 | 224 |
| 4 | 1784 |
| 5 | 13692 |
| 6 | 102036 |
| 7 | 745432 |
| 8 | 5374192 |
| 9 | 38400500 |
| 10 | 272709644 |
| 11 | 1928498640 |
| 12 | 13597146600 |
| 13 | 95668307308 |
| 14 | 672119557252 |
| 15 | 4717043931848 |
| 16 | 33080342679008 |
| 17 | 231867574534116 |
| 18 | 1624598900644860 |
| 19 | 11379821699045056 |