login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A323104 Numbers k such that 409*2^k+1 is prime. 0
2, 6, 18, 110, 186, 318, 398, 1922, 3290, 4346, 5042, 6638, 8306, 59066, 66758, 182198, 214406, 260810, 709350, 947018, 1384346, 1546542 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..22.

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(409*2^k+1), [$1..1000]); # Muniru A Asiru, Jan 04 2019

MATHEMATICA

Select[Range[1000], PrimeQ[409*2^# + 1] &]

CROSSREFS

Sequence in context: A347727 A308549 A212653 * A208456 A056743 A064535

Adjacent sequences:  A323101 A323102 A323103 * A323105 A323106 A323107

KEYWORD

nonn,more,hard

AUTHOR

Robert Price, Jan 04 2019

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 20 22:20 EDT 2021. Contains 347596 sequences. (Running on oeis4.)