\ Art Hampton's Ramanujan's cube program of 10/8/93
\ transcribed into TF83 by VHV, 8/29/05
2VARIABLE pair1
2VARIABLE sum1
: prcubed ( --) ." cubed " ;
: cubed   ( n -- D) DUP DUP * UM* ;
: testcubes ( --)  pair1 2@ 7 +     \ magic loop arguments
   DO I cubed
      pair1 2@ DROP I              \ yet again magic!
        DO 2DUP I cubed D+  sum1 2@
          D= IF  CR
            pair1 2@ 2 U.R prcubed ." + " 2 U.R prcubed ." = "
            I 2 U.R prcubed ." + " J 2 U.R prcubed ." = "
            sum1 2@ 5 UD.R
             LEAVE
             THEN
        LOOP 2DROP
   LOOP ;

: sumcubes ( --)      DARK
  18  1                       \ magic numbers found by testing
  DO I  pair1 !               \ save the first integer
     I cubed                  \ the first integer cubed
       41 I 11 +              \ more magic loop arguments
         DO I pair1 2+ !      \ save the second integer
           2DUP I cubed D+    \ the sum of the cubes of the first pr
           sum1 2!            \ to pass into variable is easier than on the stack
           testcubes
         LOOP 2DROP
  LOOP  CR ;