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 | 1 |
| 3 | -2 |
| 4 | 2 |
| 5 | -6 |
| 6 | 3 |
| 7 | -16 |
| 8 | 17 |
| 9 | -34 |
| 10 | 47 |
| 11 | -78 |
| 12 | 153 |
| 13 | -178 |
| 14 | 373 |
| 15 | -530 |
| 16 | 954 |
| 17 | -1410 |
| 18 | 2280 |
| 19 | -3896 |
| 20 | 5908 |
| 21 | -9988 |
| 22 | 15170 |
| 23 | -25908 |
| 24 | 40659 |
| 25 | -65136 |
| 26 | 105967 |
| 27 | -169056 |
| 28 | 276483 |
| 29 | -435624 |
| 30 | 712052 |
| 31 | -1139814 |
| 32 | 1839535 |
| 33 | -2955466 |
| 34 | 4745201 |
| 35 | -7689672 |
| 36 | 12303439 |
| 37 | -19866340 |
| 38 | 31904000 |