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A101421
Numbers which are the sum of two positive cubes and divisible by 7.
7
28, 35, 91, 126, 133, 189, 217, 224, 280, 539, 637, 686, 728, 756, 854, 945, 1001, 1008, 1064, 1358, 1456, 1512, 1547, 1729, 1736, 1792, 2198, 2205, 2240, 2261, 2331, 2457, 2709, 2926, 3059, 3087, 3402, 3500, 3528, 3591, 4123, 4221, 4312, 4375, 4914, 4921
OFFSET
1,1
LINKS
MATHEMATICA
upto[n_] := Block[{t}, Union@ Reap[Do[If[Mod[t = x^3 + y^3, 7] == 0, Sow@t], {x, n^(1/3)}, {y, Min[x, (n - x^3)^(1/3)]}]][[2, 1]]]; upto[5000] (* Giovanni Resta, Jun 12 2020 *)
CROSSREFS
Cf. A003325.
Sequence in context: A146077 A260637 A143186 * A039347 A043170 A043950
KEYWORD
nonn
AUTHOR
Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Jan 17 2005
EXTENSIONS
Changed offset from 0 to 1 by Vincenzo Librandi, May 08 2013
STATUS
approved