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A085366
Semiprimes that are the sum of two positive cubes. Common terms of A003325 and A046315.
5
9, 35, 65, 91, 133, 217, 341, 407, 559, 737, 793, 1027, 1241, 1339, 1343, 1843, 1853, 2071, 2413, 2771, 2869, 3197, 3383, 3439, 3473, 4097, 4439, 5129, 5833, 6119, 6641, 7471, 7859, 8027, 8587, 9773, 10261, 10649, 10991, 11377, 12679, 12913, 14023
OFFSET
1,1
COMMENTS
Sum of two positive cubes x^3 + y^3 such that both x+y and x^2 - x*y + y^2 are primes.
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
EXAMPLE
a(2) = 35 because 3^3 + 2^3 = 5*7.
a(5) = 133 = 5^3 + 2^3 = (5+2)*(5^2 - 5*2 + 2^2) = 7*19.
CROSSREFS
KEYWORD
nonn
AUTHOR
Hugo Pfoertner, Jun 25 2003
STATUS
approved