

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
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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).
Shahar Amitai, Python code to generate all primitive taxicab numbers up to N.
H. Nakao, Ramanujan Taxi Numbers [1...1000000000]
Eric Weisstein's World of Mathematics, Cubic Number


CROSSREFS

Cf. A001235.
Sequence in context: A242880 A001235 A343708 * A062924 A130859 A245671
Adjacent sequences: A018847 A018848 A018849 * A018851 A018852 A018853


KEYWORD

nonn


AUTHOR

David W. Wilson


STATUS

approved



