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A038856
Numbers ending with '1' that are the difference of two positive cubes.
0
61, 91, 271, 331, 511, 631, 721, 1141, 1261, 1701, 1801, 1951, 1981, 2401, 2611, 2791, 3311, 3571, 3781, 3971, 4401, 4501, 4681, 4921, 5131, 5831, 5941, 6211, 6851, 7271, 7351, 7651, 8071, 8261, 8451, 8911, 9241, 10621, 10981, 11951, 12481, 12691, 12871
OFFSET
1,1
MATHEMATICA
f2[upto_]:=Module[{maxno=Floor[(3+Sqrt[12*upto-3])/6]}, Select[Union[Last[#]-First[ #]& /@Subsets[Range[maxno]^3, {2}]], #<=upto&&Last[IntegerDigits[#]]==1&]]; f[13000] (* Harvey P. Dale, Mar 03 2011 *)
CROSSREFS
Sequence in context: A047272 A123207 A309180 * A144970 A045562 A104229
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
Corrected and extended by Ray Chandler, Nov 29 2008
STATUS
approved