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 | 3 |
| 2 | 8 |
| 3 | 18 |
| 4 | 32 |
| 5 | 48 |
| 6 | 128 |
| 7 | 528 |
| 8 | 512 |
| 9 | -6912 |
| 10 | 2048 |
| 11 | 357888 |
| 12 | 8192 |
| 13 | -22351872 |
| 14 | 32768 |
| 15 | 1903822848 |
| 16 | 131072 |
| 17 | -209865080832 |
| 18 | 524288 |
| 19 | 29088886161408 |
| 20 | 2097152 |
| 21 | -4951498048929792 |
| 22 | 8388608 |
| 23 | 1015423886523629568 |
| 24 | 33554432 |
| 25 | -246921480190140874752 |
| 26 | 134217728 |
| 27 | 70251601603944228323328 |