Monthly Archives: October 2014

Pattern code – arrows

Here are some arrows, all different, and all labelled.
Pattern code arrows

What should be the label of the arrow in the center?

You can check your solution here


A square

Intro whats next numbersWhat is the smallest number of which the square ends with three identical digits? And indeed, 0 is excluded as a solution.
This is a slightly simplified version of a problem published as perplexity 466 by Henry Dudeney in The Strand magazine august 1919.

You can check your solution here


Crosswords are among the worlds most printed and devised puzzles. And though they are puzzles with words, they are not language puzzles and they can be fairly easily generated once you have a large dictionary in electronic form available.

But Crosswords are so common place I have thus far avoided them in this blog. There are several number variants however, and the one presented here is geared towards math buffs.

Crossnumbers math buffs exercise

Horizontal Vertical
1 square with identical first and third digit
3 fibonacci number
5 perfect number
7 number of cards in bridge
9 happy number
10 catalan number
11 monodigit number
12 lucas number
14 happy number
16 narcistic number
18 circular prime
19 fibonacci number
1 factorial number
2 prime number
3 fourth power
4 catalan number
6 multiple of 11
8 third power
9 perfect number
12 third power and a square
13 fibonnacci number
15 triangular number
16 fermat prime
17 square

You can check your solution here