text: Try all possible pairs ( j , k ) whose cube sums can be i .
code: for ( $ j = 1 ; $ j <= pow ( $ i , 1.0 / 3 ) ; $ j ++ ) for ( $ k = $ j + 1 ; $ k <= pow ( $ i , 1.0 / 3 ) ; $ k ++ ) if ( $ j * $ j * $ j + $ k * $ k * $ k == $ i ) $ int_count ++ ;