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A024967 Positions of primes in A003072.

%I A024967 #9 Aug 27 2019 17:49:24
%S A024967 1,3,5,7,11,17,25,28,34,38,39,41,46,48,53,57,68,72,73,77,80,91,100,
%T A024967 108,110,113,115,116,120,123,128,135,144,156,161,175,185,189,198,202,
%U A024967 205,217,224,231,235,245,247,252,255,267,273,275,276,278,285,297,301,304,315,320,324
%N A024967 Positions of primes in A003072.
%H A024967 Robert Israel, <a href="/A024967/b024967.txt">Table of n, a(n) for n = 1..8446</a>
%p A024967 N:= 10000: # for members of A003072 up to N
%p A024967 S:= {}:
%p A024967 for x from 1 while 3*x^3 <= N do
%p A024967   for y from x while x^3+2*y^3<=N do
%p A024967     for z from y do
%p A024967       v:= x^3+y^3+z^3;
%p A024967       if v > N then break fi;
%p A024967       S:= S union {v}
%p A024967 od od od:
%p A024967 S:= sort(convert(S,list)):
%p A024967 select(i -> isprime(S[i]),[$1..nops(S)]); # _Robert Israel_, Aug 27 2019
%K A024967 nonn
%O A024967 1,2
%A A024967 _Clark Kimberling_
%E A024967 More terms from _Sean A. Irvine_, Jul 30 2019