login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A338836 Primes p such that 2*p^2-q^2 and 2*q^2-p^2 are prime, where q is the next prime after p. 1
53, 103, 397, 479, 1049, 1499, 1901, 1931, 2161, 2243, 2707, 3863, 4211, 5227, 5669, 6551, 6703, 7537, 8167, 8231, 8663, 8941, 9067, 9497, 10651, 10789, 10861, 12619, 14033, 14173, 14431, 14639, 14797, 15187, 15497, 16223, 16703, 17609, 18457, 18481, 20261, 21313, 21803, 22133, 22247, 22279 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

EXAMPLE

a(3)=397 is in the sequence because it is prime, the next prime is 401, and 2*397^2-401^2 = 154417 and 2*401^2-397^2 = 163993 are prime.

MAPLE

N:= 100: # for the first N terms

q:= 2: count:= 0: R:= NULL:

for iter from 1 while count < N do

  p:= q; q:= nextprime(q);

  if isprime(2*p^2-q^2) and isprime(2*q^2-p^2) then

    count:= count+1; R:= R, p;

  fi

od:

R;

CROSSREFS

Sequence in context: A063363 A288619 A039476 * A061656 A141965 A141975

Adjacent sequences:  A338833 A338834 A338835 * A338837 A338838 A338839

KEYWORD

nonn

AUTHOR

J. M. Bergot and Robert Israel, Nov 11 2020

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 January 19 06:18 EST 2022. Contains 350464 sequences. (Running on oeis4.)