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A112474
Squares that are the sum of three distinct positive cubes.
2
36, 225, 729, 2304, 2809, 3481, 5041, 6084, 7056, 7569, 8100, 9216, 9604, 13456, 14400, 14641, 15625, 17956, 23409, 26244, 26569, 27889, 32400, 35344, 41616, 45369, 46656, 50176, 50625, 51076, 52900, 57600, 58564, 59536, 63001, 64009
OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
36 = 6^2 = 1^3 + 2^3 + 3^3.
MATHEMATICA
Lim=64009; sqlim=Floor[Sqrt[Lim]]; cblim=Ceiling[Lim^(1/3)]; Select[Range[sqlim]^2, MemberQ[ Union[Total/@Subsets[Range[cblim]^3, {3}]], #]&] (* James C. McMahon, Jun 04 2024 *)
PROG
(PARI) has(n)=my(x3, z); for(x=sqrtnint(n\3, 3)+1, sqrtnint(n, 3), x3=x^3; for(y=sqrtnint((n-x3)\2, 3)+1, min(x-1, sqrtnint(n-x3, 3)), if(ispower(n-x3-y^3, 3, &z) && z<y && z>0, return(1)))); 0
list(lim)=my(v=List(), t); for(n=6, sqrtint(lim\1), if(has(t=n^2), listput(v, t))); Vec(v) \\ Charles R Greathouse IV, Sep 20 2016
CROSSREFS
Intersection of A000290 and A024975.
Sequence in context: A113164 A237252 A017234 * A166329 A264522 A297656
KEYWORD
nonn
AUTHOR
Rick L. Shepherd, Sep 06 2005
EXTENSIONS
Offset corrected by Charles R Greathouse IV, Sep 20 2016
STATUS
approved