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 | 1 |
| 2 | 3 |
| 3 | 20 |
| 4 | 364 |
| 5 | 17017 |
| 6 | 2097018 |
| 7 | 674740506 |
| 8 | 568965009030 |
| 9 | 1255571292290712 |
| 10 | 7254987185250544104 |
| 11 | 109744478168199574282739 |
| 12 | 4346236474244131564253156182 |
| 13 | 450625464087974723307205504432150 |
| 14 | 122319234225590858340579679211039433810 |