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 | 1 |
| 2 | 4 |
| 3 | 25 |
| 4 | 141 |
| 5 | 1465 |
| 6 | 23313 |
| 7 | 561044 |
| 8 | 20397794 |
| 9 | 1120217646 |
| 10 | 93298660085 |
| 11 | 11806084302586 |
| 12 | 2272026396983803 |
| 13 | 664988521276834246 |