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 | 31 |
| 2 | 192 |
| 3 | 1120 |
| 4 | 6400 |
| 5 | 36288 |
| 6 | 205184 |
| 7 | 1159488 |
| 8 | 6554880 |
| 9 | 37088480 |
| 10 | 210075712 |
| 11 | 1191254688 |
| 12 | 6762782208 |
| 13 | 38434677120 |
| 14 | 218663320320 |
| 15 | 1245254943872 |
| 16 | 7098135387648 |
| 17 | 40495661150112 |
| 18 | 231220652273600 |
| 19 | 1321222104326880 |