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 | -3 |
| 2 | 5 |
| 3 | -9 |
| 4 | 17 |
| 5 | -30 |
| 6 | 52 |
| 7 | -90 |
| 8 | 154 |
| 9 | -262 |
| 10 | 446 |
| 11 | -758 |
| 12 | 1286 |
| 13 | -2182 |
| 14 | 3702 |
| 15 | -6278 |
| 16 | 10646 |
| 17 | -18054 |
| 18 | 30614 |
| 19 | -51910 |
| 20 | 88022 |
| 21 | -149254 |
| 22 | 253078 |
| 23 | -429126 |
| 24 | 727638 |
| 25 | -1233798 |
| 26 | 2092054 |
| 27 | -3547334 |
| 28 | 6014934 |
| 29 | -10199046 |
| 30 | 17293718 |
| 31 | -29323590 |
| 32 | 49721686 |
| 33 | -84309126 |
| 34 | 142956310 |