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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 14 |
| 4 | 254 |
| 5 | 9154 |
| 6 | 552034 |
| 7 | 50183832 |
| 8 | 6417140232 |
| 9 | 1098719459424 |
| 10 | 242758470248976 |
| 11 | 67260880064331216 |
| 12 | 22840933997866565184 |
| 13 | 9330599517868641290160 |
| 14 | 4514326567036815466609008 |
| 15 | 2553018492454631240215801344 |
| 16 | 1668797317379516060093446975104 |