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 | 5 |
| 2 | 40 |
| 3 | 320 |
| 4 | 2560 |
| 5 | 20480 |
| 6 | 163840 |
| 7 | 1310720 |
| 8 | 10485760 |
| 9 | 83886080 |
| 10 | 671088640 |
| 11 | 5368709120 |
| 12 | 42949672960 |
| 13 | 343597383680 |
| 14 | 2748779069440 |
| 15 | 21990232555520 |
| 16 | 175921860444160 |
| 17 | 1407374883553280 |
| 18 | 11258999068426240 |