Jigsaw puzzles come in very different shapes and sizes, but there are some constraints.
We will call a number a jigsaw number if it is the number of pieces of a jigsaw puzzle whose length is less than twice its width. For instance, 48 is a jigsaw number because and ; but 32 is not a jigsaw number because its decompositions , , or do not have a length less than twice its width.
How many jigsaw numbers are there such that ?
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Mathematica
Length@Select[Range[1001,9999],#[[2]]<2#[[1]]&@Quantile[Divisors@#,{.5,.51}]&]
2562