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 | 20 |
| 3 | 350 |
| 4 | 6000 |
| 5 | 102500 |
| 6 | 1750000 |
| 7 | 29875000 |
| 8 | 510000000 |
| 9 | 8706250000 |
| 10 | 148625000000 |
| 11 | 2537187500000 |
| 12 | 43312500000000 |
| 13 | 739390625000000 |
| 14 | 12622187500000000 |
| 15 | 215474218750000000 |
| 16 | 3678375000000000000 |