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A018850
Numbers that are the sum of 2 cubes in more than 1 way (primitive solutions).
4
1729, 4104, 20683, 39312, 40033, 64232, 65728, 134379, 149389, 171288, 195841, 216027, 327763, 402597, 439101, 443889, 515375, 684019, 704977, 805688, 842751, 920673, 955016, 984067, 994688, 1009736, 1016496, 1073375, 1092728, 1331064
OFFSET
1,1
COMMENTS
Nakao's table has more entries because he lists nonprimitive numbers if they are the sum of two cubes in three ways.
Rajesh Bhowmick, Dec 12 2011: The odd number 40533595075161 can be represented as sum of two cubes in just two different ways: (34314)^(3)+(5073)^(3) = (34321)^(3)+(4730)^(3). Here, the cubes are greater than 1, there is no common factor between the odd numbers, there is no common factor between the L.H.S & the R.H.S, the even number is greater than 2, the cubes are in their primitive form, and they are not of the form (27)^(3) or (121)^(3) (which are actually (3)^(9) & (11)^(6)).
LINKS
Shahar Amitai, Table of n, a(n) for n = 1..9859 (terms a(1)-a(1694) from T. D. Noe).
Eric Weisstein's World of Mathematics, Cubic Number
CROSSREFS
Cf. A001235.
Sequence in context: A242880 A001235 A343708 * A062924 A350270 A130859
KEYWORD
nonn
STATUS
approved