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) |
|---|---|
| 2 | 1 |
| 3 | 10 |
| 4 | 167 |
| 5 | 1720 |
| 6 | 24164 |
| 7 | 256116 |
| 8 | 3392843 |
| 9 | 36703824 |
| 10 | 472592916 |
| 11 | 5188948072 |
| 12 | 65723863196 |
| 13 | 729734918432 |
| 14 | 9145847808784 |
| 15 | 102432266545800 |
| 16 | 1274461449989715 |
| 17 | 14373136466094880 |
| 18 | 177882700353757460 |
| 19 | 2017523504473479992 |
| 20 | 24868664942648145372 |