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) |
|---|---|
| 1 | -1 |
| 2 | 0 |
| 3 | -1 |
| 4 | 0 |
| 5 | -1 |
| 6 | 1 |
| 7 | 1 |
| 8 | 1 |
| 9 | 1 |
| 10 | 5 |
| 11 | 19 |
| 12 | 17 |
| 13 | 29 |
| 14 | 13 |
| 15 | 21 |
| 16 | 13 |
| 17 | 47 |
| 18 | 181 |
| 19 | 503 |
| 20 | 593 |
| 21 | 533 |
| 22 | 121 |
| 23 | 1259 |
| 24 | 1457 |
| 25 | 6889 |
| 26 | 7549 |
| 27 | 7109 |
| 28 | 7769 |
| 29 | 52403 |
| 30 | 59333 |
| 31 | 11497 |
| 32 | 6095 |
| 33 | 29089 |
| 34 | 61643 |
| 35 | 59333 |
| 36 | 63953 |
| 37 | 62413 |
| 38 | 7277 |
| 39 | 21061 |
| 40 | 2777 |
| 41 | 10877 |
| 42 | 11647 |
| 43 | 3809 |
| 44 | 3963 |
| 45 | 1438 |
| 46 | 271 |
| 47 | 3064 |
| 48 | 51439 |
| 49 | 7217 |
| 50 | 7493 |