OFFSET
1,1
COMMENTS
EXAMPLE
MATHEMATICA
A000043 = {2, 3, 5, 7, 13, 17, 19, 31, 61, 89, 107, 127, 521, 607, 1279, 2203, 2281, 3217, 4253, 4423, 9689, 9941, 11213, 19937, 21701, 23209, 44497, 86243, 110503, 132049, 216091, 756839, 859433, 1257787, 1398269, 2976221, 3021377, 6972593, 13466917, 20996011, 24036583, 25964951, 30402457, 32582657};
lst = {}; maxk = 5000; maxn = 15;
For[n = 1, n ≤ maxn, n++,
For[k = 0, k ≤ maxk, k++,
If[PrimeQ[k*(2^(2*A000043[[n]]) - 1) + 1], AppendTo[lst, k]; Break[]]
]
];
lst (* Robert Price, Apr 05 2016 *)
CROSSREFS
KEYWORD
nonn,more,hard
AUTHOR
Pierre CAMI, Jan 28 2016
STATUS
approved