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 | -2 |
| 2 | 8 |
| 3 | -16 |
| 4 | 18 |
| 5 | -32 |
| 6 | 112 |
| 7 | -192 |
| 8 | 0 |
| 9 | 62 |
| 10 | 1840 |
| 11 | -3312 |
| 12 | -8320 |
| 13 | 16480 |
| 14 | 71840 |
| 15 | -137280 |
| 16 | -522174 |
| 17 | 1011392 |
| 18 | 4107960 |
| 19 | -7945008 |
| 20 | -32457600 |
| 21 | 62909120 |
| 22 | 261338416 |
| 23 | -506930112 |
| 24 | -2129035776 |
| 25 | 4133297534 |
| 26 | 17531850576 |
| 27 | -34058050240 |
| 28 | -145663683072 |
| 29 | 283125653280 |
| 30 | 1219649036576 |
| 31 | -2371704375168 |
| 32 | -10281070960128 |
| 33 | 20000146662464 |
| 34 | 87178011852896 |