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A038847 Odd numbers that are differences between two positive cubes.

%I A038847 #21 Jan 22 2019 05:11:17
%S A038847 7,19,37,61,63,91,117,127,169,189,215,217,271,279,331,335,387,397,469,
%T A038847 485,511,513,547,631,657,665,721,817,819,875,919,973,999,1027,1115,
%U A038847 1141,1197,1261,1267,1323,1385,1387,1413,1519,1603,1647,1657,1685,1701
%N A038847 Odd numbers that are differences between two positive cubes.
%H A038847 Robert Israel, <a href="/A038847/b038847.txt">Table of n, a(n) for n = 1..10000</a>
%p A038847 N:= 2000: # to get all terms <= N
%p A038847 S:= {}:
%p A038847 for x from 1 to floor(1/2 + sqrt(12*N-3)/6) do
%p A038847   S:= S union {seq(x^3-y^3, y= x-1..max(1,ceil(surd(x^3-N,3))),-2)}
%p A038847 od:
%p A038847 sort(convert(S,list)); # _Robert Israel_, Jan 21 2019
%t A038847 With[{nn=50},Take[Select[Union[Abs[#[[2]]-#[[1]]]&/@Subsets[Range[nn]^3,{2}]],OddQ],nn]] (* _Harvey P. Dale_, Jan 18 2013 *)
%Y A038847 Cf. A038848.
%Y A038847 Odd terms of A181123.
%K A038847 nonn
%O A038847 1,1
%A A038847 _Jeff Burch_
%E A038847 Definition corrected by _Robert Israel_, Jan 21 2019