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 | 21 |
| 2 | 399 |
| 3 | 6783 |
| 4 | 102249 |
| 5 | 1370565 |
| 6 | 16991415 |
| 7 | 216411615 |
| 8 | 3146775345 |
| 9 | 49819225365 |
| 10 | 767467173375 |
| 11 | 11808542505375 |
| 12 | 208290421179225 |
| 13 | 4084751136190725 |
| 14 | 76593243172220775 |
| 15 | 1426967042034909375 |