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Advent calendar 2018
11 December
All 2018 advent puzzles
~
More information
This puzzle is inspired by
a puzzle Woody showed me at MathsJam
.
Today's number is the number \(n\) such that $$\frac{216!\times215!\times214!\times...\times1!}{n!}$$ is a square number.
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By the same method as
this puzzle
, the answer is
108
.
Tags:
numbers
,
square numbers
,
factorials
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digits
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integration
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hexagons
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2d shapes
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consecutive numbers
even numbers
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lists
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indices
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coins
area
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sets
means
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taxicab geometry
powers
digital clocks
averages
median
consecutive integers
squares
sequences
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graphs
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quadratics
pentagons
the only crossnumber
balancing
partitions
bases
chocolate
angles
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tournaments
multiplication
remainders
tiling
number
coordinates
scales
integers
cryptic crossnumbers
algebra
speed
spheres
arrows
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perfect numbers
colouring
wordplay
square numbers
fractions
cards
xor
division
probability
3d shapes
functions
cube numbers
multiplaction squares
numbers
medians
ave
quadrilaterals
factors
logic
factorials
pascal's triangle
cryptic clues
floors
rectangles
money
rugby
advent
square roots
gerrymandering
chess
lines
regular shapes
digital products
determinants
crosswords
geometry
folding tube maps
circles
prime factors
time
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chalkdust crossnumber
dominos
shapes
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ellipses
clocks
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multiples
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volume
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