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A038847
Odd numbers that are differences between two positive cubes.
1
7, 19, 37, 61, 63, 91, 117, 127, 169, 189, 215, 217, 271, 279, 331, 335, 387, 397, 469, 485, 511, 513, 547, 631, 657, 665, 721, 817, 819, 875, 919, 973, 999, 1027, 1115, 1141, 1197, 1261, 1267, 1323, 1385, 1387, 1413, 1519, 1603, 1647, 1657, 1685, 1701
OFFSET
1,1
LINKS
MAPLE
N:= 2000: # to get all terms <= N
S:= {}:
for x from 1 to floor(1/2 + sqrt(12*N-3)/6) do
S:= S union {seq(x^3-y^3, y= x-1..max(1, ceil(surd(x^3-N, 3))), -2)}
od:
sort(convert(S, list)); # Robert Israel, Jan 21 2019
MATHEMATICA
With[{nn=50}, Take[Select[Union[Abs[#[[2]]-#[[1]]]&/@Subsets[Range[nn]^3, {2}]], OddQ], nn]] (* Harvey P. Dale, Jan 18 2013 *)
CROSSREFS
Cf. A038848.
Odd terms of A181123.
Sequence in context: A301717 A152540 A073859 * A130056 A136057 A177092
KEYWORD
nonn
AUTHOR
EXTENSIONS
Definition corrected by Robert Israel, Jan 21 2019
STATUS
approved