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A171385
Sum of a positive square and a positive cube in at least three ways.
1
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
OFFSET
1,1
COMMENTS
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
EXAMPLE
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.
MAPLE
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
CROSSREFS
Cf. A054402, integers with two or more such representations.
Sequence in context: A351310 A045035 A060948 * A031742 A353943 A351273
KEYWORD
easy,nonn
AUTHOR
Alan Frank, Dec 07 2009
EXTENSIONS
More terms from R. J. Mathar, Dec 11 2009
STATUS
approved