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A122732 3-almost primes that are the sum of 2 positive cubes. Sums of 2 positive cubes, with the sums having exactly 3 prime divisors counted with multiplicity.

%I A122732 #11 Feb 05 2017 02:54:39
%S A122732 28,370,539,637,730,854,1001,1358,1547,1729,2198,2261,3059,3887,3925,
%T A122732 4075,4123,4706,4825,4921,5038,5957,6293,6886,6923,7075,7163,7202,
%U A122732 7657,8029,8729,9262,9269,9325,9331,10745,10955,11458,12175,12383,12845
%N A122732 3-almost primes that are the sum of 2 positive cubes. Sums of 2 positive cubes, with the sums having exactly 3 prime divisors counted with multiplicity.
%C A122732 3-almost prime analog of A085366 Semiprimes that are the sum of two positive cubes. The sum of two positive cubes cannot be prime.
%H A122732 Giovanni Resta, <a href="/A122732/b122732.txt">Table of n, a(n) for n = 1..10000</a>
%F A122732 A003325 INTERSECTION A014612. {x = a^3 + b^3 for positive integers a, b, such that A001222(x) = 3}.
%e A122732 a(1) = 28 = 2^2 * 7 = 1^3 + 3^3.
%e A122732 a(2) = 370 = 2 * 5 * 37 = 3^3 + 7^3.
%e A122732 a(3) = 539 = 7^2 * 11 = 2^3 + 8^3.
%e A122732 a(4) = 637 = 7^2 * 13 = 5^3 + 8^3.
%e A122732 a(5) = 730 = 2 * 5 * 73 = 1^3 + 9^3.
%e A122732 a(6) = 854 = 2 * 7 * 61 = 5^3 + 9^3.
%e A122732 a(7) = 1001 = 7 * 11 * 13 = 1^3 + 10^3.
%o A122732 (PARI) is(n)=bigomega(n)==3 && #select(v->min(v[1], v[2])>0, thue('x^3+1, n))>0 \\ _Charles R Greathouse IV_, Feb 05 2017
%Y A122732 Cf. A000578, A001222, A003325, A014612.
%K A122732 easy,nonn
%O A122732 1,1
%A A122732 _Jonathan Vos Post_, Sep 23 2006
%E A122732 More terms from _R. J. Mathar_, Jan 27 2009