The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 3 |
| 3 | -1 |
| 4 | 5 |
| 5 | 7 |
| 6 | -1 |
| 7 | -1 |
| 8 | 11 |
| 9 | 17 |
| 10 | 23 |
| 11 | -1 |
| 12 | 19 |
| 13 | -1 |
| 14 | 31 |
| 15 | 73 |
| 16 | 29 |
| 17 | -1 |
| 18 | 383 |
| 19 | -1 |
| 20 | 41 |
| 21 | 97 |
| 22 | -1 |
| 23 | -1 |
| 24 | 79 |
| 25 | -1 |
| 26 | -1 |
| 27 | 127 |
| 28 | 223 |
| 29 | -1 |
| 30 | 71 |
| 31 | -1 |
| 32 | 109 |
| 33 | -1 |
| 34 | -1 |
| 35 | 2593 |
| 36 | 197 |
| 37 | -1 |
| 38 | -1 |
| 39 | -1 |
| 40 | 281 |
| 41 | -1 |
| 42 | 1439 |
| 43 | -1 |
| 44 | 34303 |
| 45 | 199 |
| 46 | -1 |
| 47 | -1 |
| 48 | 181 |
| 49 | -1 |
| 50 | 647 |
| 51 | -1 |
| 52 | 6143 |
| 53 | -1 |
| 54 | 7057 |
| 55 | -1 |
| 56 | 929 |
| 57 | -1 |
| 58 | -1 |
| 59 | -1 |
| 60 | 521 |
| 61 | -1 |
[2,3,-1,5,7,-1,-1,11,17,23,-1,19,-1,31,73,29,-1, 383,-1,41,97,-1,-1,79,-1,-1,127,223,-1,71,-1,109, -1,-1,2593,197,-1,-1,-1,281,-1,1439,-1,34303,199, -1,-1,181,-1,647,-1,6143,-1,7057,-1,929,-1,-1,-1, 521,-1] |