|
%I #6 Aug 12 2015 10:17:07
%S 5,11,29,461,599,659,809,1019,1289,2027,2141,2309,2339,2801,3329,3557,
%T 3581,4127,4421,4547,5879,6761,10091,10457,10709,13829,15329,18911,
%U 20231,21839,23561,23909,26249,26879,27581,27689,27917,28109,30491
%N Lesser of twin primes p1 such that p1+(p2^2-p1^2) and p2+(p2^2-p1^2) are prime numbers.
%C 5+(7^2-5^2)=5+24=29; 7+(7^2-5^2)=7+24=31,..
%H Harvey P. Dale, <a href="/A174922/b174922.txt">Table of n, a(n) for n = 1..1000</a>
%t lst={};Do[p1=Prime[n];p2=p1+2;If[PrimeQ[p2]&&PrimeQ[p1+(p2^2-p1^2)]&&PrimeQ[p2+(p2^2-p1^2)],AppendTo[lst,p1]],{n,8!}];lst
%t prQ[{a_,b_}]:=Module[{c=b^2-a^2},AllTrue[{a+c,b+c},PrimeQ]]; Transpose[ Select[ Select[ Partition[Prime[Range[5000]],2,1],#[[2]]-#[[1]] == 2&], prQ]][[1]] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Aug 12 2015 *)
%Y Cf. A001359, A174913, A174915, A174916, A174917, A174920
%K nonn
%O 1,1
%A _Vladimir Joseph Stephan Orlovsky_, Apr 02 2010
|
