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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 0 |
| 5 | -1 |
| 6 | 1 |
| 7 | 1 |
| 8 | -1 |
| 9 | -2591989 |
| 10 | 1 |
| 11 | 143285617 |
| 12 | -576460261 |
| 13 | -56447987 |
| 14 | 3300470359 |
| 15 | 3143536325702272141 |
| 16 | -1786064113 |
| 17 | -75094364111707432631 |
| 18 | 2817261842693900500163 |
| 19 | 669559278432109042489 |
| 20 | -328057861344412119208697 |
| 21 | -10210033960347221028684507558893 |
| 22 | 4858439165868890899345523 |