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 | 1 |
| 1 | 4 |
| 2 | 40 |
| 3 | 602 |
| 4 | 11384 |
| 5 | 253698 |
| 6 | 6495616 |
| 7 | 187940402 |
| 8 | 6055160152 |
| 9 | 214444348674 |
| 10 | 8261055193008 |
| 11 | 343357357970866 |
| 12 | 15298169514407880 |
| 13 | 726752780487465922 |
| 14 | 36642712015230282784 |
| 15 | 1952976182776961017138 |