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 | -1 |
| 5 | 0 |
| 6 | -1 |
| 7 | 2 |
| 8 | 1 |
| 9 | 5 |
| 10 | 6 |
| 11 | 14 |
| 12 | 15 |
| 13 | 32 |
| 14 | 40 |
| 15 | 64 |
| 16 | 86 |
| 17 | 131 |
| 18 | 166 |
| 19 | 237 |
| 20 | 287 |
| 21 | 362 |
| 22 | 389 |
| 23 | 368 |
| 24 | 149 |
| 25 | -339 |
| 26 | -1477 |
| 27 | -3680 |
| 28 | -7827 |
| 29 | -15245 |
| 30 | -28270 |
| 31 | -50493 |
| 32 | -87886 |
| 33 | -149827 |
| 34 | -250966 |
| 35 | -414542 |
| 36 | -675741 |
| 37 | -1089267 |
| 38 | -1736640 |
| 39 | -2741788 |
| 40 | -4284837 |
| 41 | -6632751 |
| 42 | -10162683 |
| 43 | -15412613 |
| 44 | -23110653 |
| 45 | -34236290 |