King Walking

 

[July, 23rd, 2010]

 

Hello SeqFans,

 

In this 4x5 box one can read all consecutive integers from 0 to 158 (included):

 

  5 8 0 7 3

  9 6 5 1 8

  1 3 2 4 2

  4 0 9 7 6

 

(grid submitted by James Dow Allen on rec.puzzles two days ago)

 

The rules are:

- an integer is there if it’s digits can be walked on by a chess King (one step in 8 directions: 4 straightly, 4 diagonally)

- two identical digits (or more) can follow each other (as if the King was jumping on the same square).

 

Example:

- the integers 58073, 13997 and 13887 are visible below,

- the integer 159 is not:

 

  5 8 0 7 3

  9 6 5 1 8

  1 3 2 4 2

  4 0 9 7 6

 

It seems impossible to find such a 4x5 box showing all consecutive integers from 0 to ‘n’ with ‘n’ > 158.

 

Here is Giovanni Resta’s 158 solution or the same box published on rec.puzzles yesterday):

 

  0 3 6 4 2

  1 7 5 1 3

  4 0 2 8 9

  8 9 6 5 7

Question:

Using the same rules, what would be the highest reachable integer in the successive square boxes 1x1, 2x2, 3x3, 4x4, 5x5, ...

This might constitute a seq S for Neil. [S starts 0, 3, 8, ...]

Best,

Ι.

__________

 

[Andrew Weimholt]:

 

> The next term is at least 58

 

8 3 4 9

2 0 7 2

1 6 5 1

9 3 4 8

 

I looked a little closer at this one tonight, and I can now also confirm that 58 is the next term.

__________

 

[Dmitri Kamenetsky]:

 

Hi Eric,

 

What an interesting problem, thank you! This problem seems perfect for our competitions: http://www.v-sonline.com/index.pl

I will propose the problem and if it gets accepted then we will probably explore all NxN squares with N from 3 to 32.

 

__________

 

... and so it was – the contest asking though for N to be kept between 4 and 13. The sequence (including the substring “0”, which was not specified on SeqFans) is currently this one (September 1st, 2010):

 

S = 1, 4, 9, 59, 369, 1867, 6389, 37138, 137095, 384057, 490158, 1603594, 4039068, ...

 

To be followed ?

Best,

Ι.

 

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