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Sum of two (possibly negative) cubes in at least 3 ways.
4

%I #14 Oct 26 2017 03:00:09

%S 728,3367,4104,5824,5859,19656,26936,32832,46592,46683,46872,65728,

%T 68913,90909,91000,101528,110808,124488,134379,152551,155736,157248,

%U 158193,165464,168112,184464,195841,205352,215488,249704,262656

%N Sum of two (possibly negative) cubes in at least 3 ways.

%H Chai Wah Wu, <a href="/A051383/b051383.txt">Table of n, a(n) for n = 1..34042</a>

%e 4104 = 18^3 + (-12)^3 = 16^3 + 2^3 = 15^3 + 9^3, so 4104 is in the sequence.

%o (PARI) is(n)=#thue(thueinit(z^3+1),n)>4 \\ _Ralf Stephan_, Oct 18 2013

%Y Cf. A051347, A051384.

%K nonn

%O 1,1

%A _Colin Mallows_