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A248620 Lesser of twin primes of (29n + 1, 29n + 3). 2

%I #39 Mar 16 2019 18:52:20

%S 59,1277,1451,3539,4931,5279,9281,9629,10499,11717,12239,16067,22157,

%T 23027,23201,24419,26681,31727,34511,35729,37991,40427,45821,47387,

%U 48779,55217,59219,60089,70181,70877,72269,75401,77489,79229,80447,83231,85667,88799

%N Lesser of twin primes of (29n + 1, 29n + 3).

%C Lesser of twin primes where A195819(n) + 1 and A195819(n) + 3 are both primes.

%C Intersection of A001359 and A141977.

%H Karl V. Keller, Jr., <a href="/A248620/b248620.txt">Table of n, a(n) for n = 1..1000</a>

%e 29 * 2 + 1 = 59, which is prime, and 61 is also prime, so 59 is in the sequence.

%e 29 * 44 + 1 = 1277, which is prime, and 1279 is also prime, so 1277 is in the sequence.

%e 29 * 50 + 1 = 1451, which is prime, and 1453 is also prime, so 1451 is in the sequence.

%e 29 * 54 + 1 = 1567, which is prime, but 1569 = 3 * 523, so 1567 is not in the sequence.

%t Select[58Range[1500] + 1, PrimeQ[#] && PrimeQ[# + 2] &] (* _Alonso del Arte_, Oct 31 2014 *)

%t Select[29*Range[2,3150,2],AllTrue[#+{1,3},PrimeQ]&]+1 (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Mar 16 2019 *)

%o (Python)

%o from math import *

%o from sympy import isprime

%o for n in range(0,10001):

%o ..if isprime(58*n+1) and isprime(58*n+3): print (58*n+1,end=', ')

%o (PARI) lista(nn) = {forstep (n=2, nn, 2, if (isprime(p=29*n+1) && isprime(29*n+3), print1(p, ", ")););} \\ _Michel Marcus_, Oct 17 2014

%Y Cf. A001359 (Lesser of twin primes), A195819 (Multiples of 29).

%Y Cf. A141977 (Primes congruent to 1 mod 29), A141979 (Primes congruent to 3 mod 29).

%K nonn

%O 1,1

%A _Karl V. Keller, Jr._, Oct 10 2014

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