cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A270244 Lesser of twin primes such that the sum of the twin prime pair is the sum of 2 positive cubes.

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%I A270244 #14 Mar 17 2016 05:59:36
%S A270244 1871,8819,74609,77237,81647,93131,98927,102059,108107,110501,152837,
%T A270244 180287,220859,241919,256031,275939,309851,319679,422099,457001,
%U A270244 459647,462419,490247,530711,568151,635291,660851,667547,721619,729269,761669,843677,859679,909971,948401,1037087,1041119
%N A270244 Lesser of twin primes such that the sum of the twin prime pair is the sum of 2 positive cubes.
%H A270244 Chai Wah Wu, <a href="/A270244/b270244.txt">Table of n, a(n) for n = 1..10000</a>
%e A270244 1871 is a term because 1871 + 1873 = 10^3 + 14^3.
%e A270244 8819 is a term because 8819 + 8821 = 4^3 + 26^3.
%e A270244 74609 is a term because 74609 + 74611 = 7^3 + 53^3.
%t A270244 Select[Select[Prime@ Range[10^5], PrimeQ[# + 2] &], Length[PowersRepresentations[2 # + 2, 2, 3] /. {0, _} -> Nothing] > 0 &] (* _Michael De Vlieger_, Mar 15 2016 *)
%o A270244 (PARI) isA003325(n) = for(k=1, sqrtnint(n\2, 3), ispower(n-k^3, 3) && return(1));
%o A270244 t(n,p=3) = {while( p+2 < (p=nextprime( p+1 )) || n-->0, ); p-2}
%o A270244 for(n=1, 1e4, if(isA003325(2*t(n)+2), print1(t(n), ", ")));
%Y A270244 Cf. A001359, A003325, A054735.
%K A270244 nonn
%O A270244 1,1
%A A270244 _Altug Alkan_, Mar 13 2016