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A323151
Numbers k such that 445*2^k+1 is prime.
1
4, 8, 10, 22, 40, 52, 56, 58, 136, 152, 154, 208, 316, 356, 364, 472, 752, 1006, 1244, 2324, 2684, 3980, 5468, 8552, 10236, 14240, 15460, 20984, 21862, 24682, 26900, 35588, 39344, 45984, 64762, 73786, 142612, 189464, 230204, 292018, 449804, 1138720, 1328250
OFFSET
1,1
COMMENTS
The associated primes are: 7121, 113921, 455681, 1866465281, 489282674360321, 2004101834179870721, 32065629346877931521, 128262517387511726081, 38764967239633309757747635278627034649067521, 2540500893016608588283749025620101342761288990721, 10162003572066434353134996102480405371045155962881. - Vincenzo Librandi, Jan 06 2019
MAPLE
select(k->isprime(445*2^k+1), [$1..1000]); # Muniru A Asiru, Jan 05 2019
MATHEMATICA
Select[Range[1000], PrimeQ[445*2^# + 1] &]
PROG
(Magma) [n: n in [1..5000] | IsPrime(445*2^n+1)]; // Vincenzo Librandi, Jan 06 2019
CROSSREFS
Sequence in context: A338312 A130442 A031073 * A037004 A136861 A109445
KEYWORD
nonn,hard
AUTHOR
Robert Price, Jan 05 2019
STATUS
approved