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Child Play.. (Posted on 2009-08-07) Difficulty: 3 of 5
111111111....or maybe not! *

A version of "hopscotch" has this layout:

D G
A B C F
E H

Replace each of the letters with a unique digit from 0 to 9 such that you "hop" from one criterion to the next:
11111 AB is Prime,
11111 BCD is a Triangle,
11111 DEF is a Square and
11111 FGH is a Fibonacci number,
111111111111111 and none begin with a zero.

What 8-digit numbers are formed by this process?
What is significant about the highest and lowest?

* This can be logically deduced albeit a little time consuming.

See The Solution Submitted by brianjn    
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Signifiers?? | Comment 5 of 10 |

Charlie's  list had one more (43516987) which my method should have picked up.  I made "short lists" of candidates for the last three tests (Triangulars 105,325,351,741; Squares 169,196,529,576;Fibonaccis 610,987) after eliminating ones with leading zero, repeated digits, or no match from the preceding or following subset.  I overlooked the seventh set, but we both have the same first and last sets.  For this one I did not use a program or a calculator, since it seemed the four subsets were small enough to inspect directly.

I have no clue what might be significant about the first and last. They factor as:

23516987 = 13 * 59 * 30661

83257610 = 2 * 5 * 821 * 10141

 


  Posted by ed bottemiller on 2009-08-07 15:05:26
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