A323103 Numbers k such that 407*2^k+1 is prime.

3, 11, 15, 23, 75, 119, 159, 215, 227, 235, 931, 979, 1147, 1727, 2495, 2827, 3219, 4787, 6191, 11815, 12823, 18619, 21203, 24547, 34115, 61455, 71495, 105091, 109115, 120827, 121203, 149607, 198907, 211167, 499431, 541955, 584491, 864871, 1013603, 1171719

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..42

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(407*2^k+1), [$1..1000]); # Muniru A Asiru, Jan 04 2019

Mathematica

Select[Range[1000], PrimeQ[407*2^# + 1] &]

Crossrefs

Sequence in context: A331831 A357440 A186302 * A046159 A022410 A146254

Adjacent sequences: A323100 A323101 A323102 * A323104 A323105 A323106

Keyword

nonn,hard

Author

Robert Price, Jan 04 2019

Status

approved