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 | -1 |
| 2 | 1 |
| 3 | -2 |
| 4 | 3 |
| 5 | -4 |
| 6 | 6 |
| 7 | -10 |
| 8 | 15 |
| 9 | -22 |
| 10 | 34 |
| 11 | -52 |
| 12 | 78 |
| 13 | -118 |
| 14 | 180 |
| 15 | -274 |
| 16 | 415 |
| 17 | -630 |
| 18 | 958 |
| 19 | -1454 |
| 20 | 2206 |
| 21 | -3350 |
| 22 | 5088 |
| 23 | -7724 |
| 24 | 11726 |
| 25 | -17806 |
| 26 | 27036 |
| 27 | -41046 |
| 28 | 62320 |
| 29 | -94624 |
| 30 | 143668 |
| 31 | -218130 |
| 32 | 331191 |
| 33 | -502854 |
| 34 | 763486 |
| 35 | -1159206 |
| 36 | 1760038 |
| 37 | -2672286 |
| 38 | 4057356 |
| 39 | -6160326 |
| 40 | 9353294 |
| 41 | -14201206 |
| 42 | 21561836 |