A323151 Numbers k such that 445*2^k+1 is prime.

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

Links

Robert Price, Table of n, a(n) for n = 1..46

Ray Ballinger, Proth Search Page

Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for 300 < k < 600

Y. Gallot, Proth.exe: Windows Program for Finding Large Primes

Wilfrid Keller, List of primes k.2^n - 1 for k < 300

Eric Weisstein's World of Mathematics, Proth Prime

Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

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

Adjacent sequences: A323148 A323149 A323150 * A323152 A323153 A323154

Keyword

nonn,hard

Author

Robert Price, Jan 05 2019

Status

approved