All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars
 perplexus dot info

 Find this cube! (Posted on 2012-06-16)
What is the smallest palindrome that is the cube of a non-palindromic number?

Comments: ( Back to comment list | You must be logged in to post comments.)
 Two solutions, one a little dubious. | Comment 3 of 4 |

Not seeing a solution in a spreadsheet, and several ill-constructed programs, one program seemed to work but the ‘non-palindromic’ count had reached a 9- or 10-digit number.  With a D3 rating something was wrong.

The problem is asking for “a palindrome that is the cube of something not palindromic”.   That was telling me that I was working with integers, but was I?

Taking that wording at face value I supposed, since a single digit is considered to be a palindrome 1 cannot be considered as both it and its root are palindromes.  2 however is the cube of 2^(1/3).

While searching for palindromic scripts I happened upon something stating that a certain value was the only known one to generate a palindromic cube, and emphasis on the word cube.

Editing my listing I the program stopped at the said result: 2201^3

‘ QB64 listing

CLS

DIM SHARED a AS DOUBLE
DIM SHARED k AS DOUBLE
DIM SHARED p\$
DIM SHARED p
a = 1

done = 0
DO
k = a
PalTest
IF p = 0 THEN
k = a ^ 3
PalTest

IF p = 1 THEN
done = 1
PRINT a, a ^ 3
PRINT "done"
END IF

END IF
a = a + 1
LOOP WHILE (done <> 1)

SUB PalTest
p = 0
p\$ = LTRIM\$(STR\$(k))
ln = LEN(p\$)
b = 1
DO
IF MID\$(p\$, b, 1) = MID\$(p\$, ln - b + 1, 1) THEN
p = 1
ELSE
p = 0
END IF
b = b + 1
LOOP WHILE (b < ln AND p <> 0)
END SUB
 Posted by brianjn on 2012-06-16 21:19:13

 Search: Search body:
Forums (0)
Random Problem
Site Statistics
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox: