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) |
|---|---|
| 1 | 10 |
| 2 | 45 |
| 3 | 330 |
| 4 | 2475 |
| 5 | 19998 |
| 6 | 166485 |
| 7 | 1428570 |
| 8 | 12498750 |
| 9 | 111111000 |
| 10 | 999989991 |
| 11 | 9090909090 |
| 12 | 83333249175 |
| 13 | 769230769230 |
| 14 | 7142856428565 |
| 15 | 66666666659934 |
| 16 | 624999993750000 |
| 17 | 5882352941176470 |
| 18 | 55555555499944500 |