mscroggs
.co.uk
mscroggs
.co.uk
blog
puzzles
academic
talks
contact
subscribe
↓ ☰ ↓
subscribe
Loading image...
Advent calendar 2015
23 December
All 2015 advent puzzles
~
More information
This number is a prime number. If you treble it and add 16, the result is also prime. Repeating this will give 11 prime numbers in total (including the number itself).
Show answer
Hide answer
587
Tags:
numbers
,
prime numbers
Archive
Show me a random puzzle
Most recent collections
Advent calendar 2025
Advent calendar 2024
Advent calendar 2023
Advent calendar 2022
List of all puzzles
Tags
albgebra
even numbers
chocolate
range
area
consecutive integers
scales
xor
sport
mean
percentages
parabolas
speed
shape
functions
dodecagons
dominos
addition
logic
prime numbers
2d shapes
quadrilaterals
calculus
irreducible numbers
cryptic crossnumbers
medians
elections
star numbers
symmetry
remainders
median
planes
games
coins
clocks
ellipses
geometric means
surds
tiling
graphs
palindromes
balancing
multiplication
sums
triangles
digital products
matrices
crossnumbers
arrows
geometry
odd numbers
time
neighbours
complex numbers
angles
decahedra
binary
rugby
fractions
hexagons
spheres
squares
indices
crosswords
polynomials
factors
doubling
sum to infinity
dice
expansions
multiplaction squares
geometric mean
products
sequences
probability
tournaments
numbers
square numbers
lines
shapes
pentagons
number
rectangles
digital clocks
integers
multiples
pascal's triangle
lists
ave
floors
taxicab geometry
partitions
factorials
unit fractions
3d shapes
gerrymandering
sets
tangents
averages
routes
differentiation
probabilty
consecutive numbers
cube numbers
bases
the only crossnumber
advent
polygons
cards
digits
menace
cryptic clues
triangle numbers
perimeter
books
money
coordinates
grids
regular shapes
cubics
chalkdust crossnumber
circles
chess
combinatorics
perfect numbers
christmas
square roots
means
prime factors
determinants
quadratics
wordplay
square grids
integration
people maths
volume
algebra
axes
trigonometry
division
folding tube maps
proportion
colouring
powers
dates
Archive
Show me a random puzzle
▼ show ▼
▲ hide ▲
Most recent collections
Advent calendar 2025
Advent calendar 2024
Advent calendar 2023
Advent calendar 2022
List of all puzzles
Tags
determinants
folding tube maps
probability
tangents
books
the only crossnumber
digits
geometric mean
shape
surds
spheres
matrices
tournaments
lines
prime numbers
number
proportion
regular shapes
decahedra
tiling
crossnumbers
triangles
ave
menace
cryptic clues
integers
arrows
parabolas
functions
balancing
consecutive numbers
area
means
triangle numbers
gerrymandering
coins
polygons
division
ellipses
digital clocks
expansions
mean
colouring
even numbers
percentages
remainders
calculus
partitions
christmas
taxicab geometry
squares
doubling
multiplaction squares
xor
digital products
time
perfect numbers
trigonometry
volume
dates
logic
wordplay
graphs
2d shapes
consecutive integers
powers
symmetry
sum to infinity
pentagons
dodecagons
circles
routes
multiplication
addition
sets
clocks
unit fractions
money
geometry
perimeter
floors
bases
crosswords
angles
quadrilaterals
complex numbers
combinatorics
cards
probabilty
binary
polynomials
fractions
rugby
multiples
averages
people maths
scales
chocolate
hexagons
elections
grids
chess
sport
indices
dice
shapes
3d shapes
pascal's triangle
products
lists
square grids
numbers
medians
advent
chalkdust crossnumber
albgebra
algebra
rectangles
dominos
coordinates
prime factors
factors
cube numbers
irreducible numbers
differentiation
cryptic crossnumbers
square roots
median
star numbers
square numbers
speed
geometric means
quadratics
integration
range
odd numbers
cubics
neighbours
sequences
games
factorials
palindromes
axes
sums
planes
© Matthew Scroggs 2012–2026