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A171385
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Sum of a positive square and a positive cube in at least three ways.
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1
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1025, 1737, 2089, 2628, 2817, 3033, 3664, 4481, 4825, 4977, 5841, 7057, 7785, 7948, 8225, 8289, 8900, 10025, 11025, 11665, 12393, 14049, 14400, 14724, 15193, 15345, 15641, 15689, 15884, 16649, 16857, 18201, 18369, 19225, 19664, 19908, 20224
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OFFSET
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1,1
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COMMENTS
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Four or more representations have 1025, 19225, 27289, 29025, 39329, 48025, 54225, 65537, 65600, 79129, 92025, 93241, 105192, 105633, 111681, ... - R. J. Mathar, Dec 11 2009
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LINKS
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EXAMPLE
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1025 = 32^2 + 1^3, 31^2 + 4^3, 30^2 + 5^3, and 5^2 + 10^3;
1737 = 35^2 + 8^3, 3^2 + 12^3, and 39^2 + 6^3.
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MAPLE
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isA171385 := proc(n) a := 0 ; for c from 1 do if c^3 >= n then break; else if issqr(n-c^3) then a := a+1 ; end if; end if; end do ; a >= 3 ; end proc: for n from 2 to 120000 do if isA171385(n) then printf("%d, ", n) ; fi; end do ; # R. J. Mathar, Dec 11 2009
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CROSSREFS
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Cf. A054402, integers with two or more such representations.
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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