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A014439
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Differences between two positive cubes in exactly 1 way.
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11
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7, 19, 26, 37, 56, 61, 63, 91, 98, 117, 124, 127, 152, 169, 189, 208, 215, 217, 218, 271, 279, 296, 316, 331, 335, 342, 386, 387, 397, 448, 469, 485, 488, 504, 511, 513, 547, 602, 604, 631, 657, 665, 702, 784, 817, 819, 866, 875, 919, 936, 973, 988, 992
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OFFSET
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1,1
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LINKS
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MAPLE
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N:= 1000: # to get all terms <= N
X:= floor(sqrt(N/3)):
V:= Vector(N):
for x from 2 to X do
if x^3 > N then
y0:= iroot(x^3-N, 3);
if x^3 - y0^3 > N then y0:= y0+1 fi;
else y0:= 1 fi;
for y from y0 to x-1 do
V[x^3 - y^3] := V[x^3 - y^3]+1
od
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MATHEMATICA
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r = 992; p = 3; Sort@Drop[Flatten@Select[Tally@Reap[Do[n = i^p - j^p; If[n <= r, Sow[n]], {i, Ceiling[(r/p)^(1/(p - 1))]}, {j, i}]][[2, 1]], #[[2]] == 1 &], {2, -1, 2}] (* Arkadiusz Wesolowski, Dec 10 2015 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Glen Burch (gburch(AT)erols.com)
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EXTENSIONS
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Corrected and extended by Don Reble, Nov 19 2006
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STATUS
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approved
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