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 | -1 |
| 4 | 2 |
| 5 | -3 |
| 6 | 4 |
| 7 | -6 |
| 8 | 9 |
| 9 | -13 |
| 10 | 18 |
| 11 | -26 |
| 12 | 38 |
| 13 | -54 |
| 14 | 77 |
| 15 | -111 |
| 16 | 160 |
| 17 | -229 |
| 18 | 328 |
| 19 | -472 |
| 20 | 679 |
| 21 | -974 |
| 22 | 1398 |
| 23 | -2010 |
| 24 | 2888 |
| 25 | -4146 |
| 26 | 5954 |
| 27 | -8555 |
| 28 | 12289 |
| 29 | -17647 |
| 30 | 25346 |
| 31 | -36410 |
| 32 | 52297 |
| 33 | -75109 |
| 34 | 107881 |
| 35 | -154961 |
| 36 | 222574 |
| 37 | -319679 |
| 38 | 459167 |
| 39 | -659528 |
| 40 | 947295 |
| 41 | -1360612 |
| 42 | 1954295 |
| 43 | -2807031 |
| 44 | 4031809 |
| 45 | -5790982 |