

A171385


Sum of a positive square and a positive cube in at least three ways.


0



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
(list;
graph;
refs;
listen;
history;
text;
internal format)



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


LINKS

Table of n, a(n) for n=1..37.


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(nc^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
Adjacent sequences: A171382 A171383 A171384 * A171386 A171387 A171388


KEYWORD

easy,nonn


AUTHOR

Alan Frank, Dec 07 2009


EXTENSIONS

More terms from R. J. Mathar, Dec 11 2009


STATUS

approved



