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 | 3 |
| 2 | 21 |
| 3 | 289 |
| 4 | 7566 |
| 5 | 380424 |
| 6 | 37361616 |
| 7 | 7252471584 |
| 8 | 2799853666176 |
| 9 | 2155959119115264 |
| 10 | 3315891500224031232 |
| 11 | 10193070293871040606464 |
| 12 | 62646640175842537242599936 |
| 13 | 769927299959295414569740867584 |
| 14 | 18923273743619678311418282019397632 |
| 15 | 930154604531789703005691292148132511744 |