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A085366 Semiprimes that are the sum of two positive cubes. Common terms of A003325 and A046315. 5

%I #13 Oct 14 2023 23:37:02

%S 9,35,65,91,133,217,341,407,559,737,793,1027,1241,1339,1343,1843,1853,

%T 2071,2413,2771,2869,3197,3383,3439,3473,4097,4439,5129,5833,6119,

%U 6641,7471,7859,8027,8587,9773,10261,10649,10991,11377,12679,12913,14023

%N Semiprimes that are the sum of two positive cubes. Common terms of A003325 and A046315.

%C Sum of two positive cubes x^3 + y^3 such that both x+y and x^2 - x*y + y^2 are primes.

%C The only square is 9. Also, all terms have a unique representation as a sum of two distinct positive cubes. - _Zak Seidov_, Jun 02 2011

%H Zak Seidov, <a href="/A085366/b085366.txt">Table of n, a(n) for n = 1..1356</a>

%e a(2) = 35 because 3^3 + 2^3 = 5*7.

%e a(5) = 133 = 5^3 + 2^3 = (5+2)*(5^2 - 5*2 + 2^2) = 7*19.

%Y Cf. A003325, A046388, A001358, A085367.

%K nonn

%O 1,1

%A _Hugo Pfoertner_, Jun 25 2003

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Last modified April 24 15:52 EDT 2024. Contains 371961 sequences. (Running on oeis4.)