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 | 1 |
| 3 | 4 |
| 4 | 32 |
| 5 | 436 |
| 6 | 9012 |
| 7 | 262760 |
| 8 | 10270696 |
| 9 | 518277560 |
| 10 | 32795928016 |
| 11 | 2542945605432 |
| 12 | 237106822506952 |
| 13 | 26173354092593696 |
| 14 | 3375693096567983232 |
| 15 | 502995942483693043200 |
| 16 | 85750135569136650473360 |
| 17 | 16583651916595710735271248 |
| 18 | 3611157196483089769387182064 |
| 19 | 879518067472225603327860638128 |