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 | 9 |
| 1 | 45 |
| 2 | 1035 |
| 3 | 536130 |
| 4 | 143717956515 |
| 5 | 10327425512495574450870 |
| 6 | 53327858858072239299138189326373798809103885 |