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 | 6 |
| 3 | 15 |
| 4 | 42 |
| 5 | 44 |
| 6 | 1365 |
| 7 | 3855 |
| 8 | 74898 |
| 9 | 44620 |
| 10 | 39672 |
| 11 | 195225786 |
| 12 | 616318176 |
| 13 | 26815350376 |
| 14 | 1186422030 |
| 15 | 663226400 |
| 16 | 1001874900 |
| 17 | 4885233465012400 |
| 18 | 1152921504606846975 |
| 19 | 10197205073773110 |
| 20 | 9758202933231640 |
| 21 | 2908370863958880 |
| 22 | 1152589154156603558 |
| 23 | 2895630705663782454386 |
| 24 | 103161669940448356241593685 |