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
triangles
functions
taxicab geometry
parabolas
determinants
folding tube maps
money
polygons
geometric mean
prime numbers
pascal's triangle
squares
factors
digits
planes
odd numbers
shape
digital products
numbers
irreducible numbers
cryptic clues
cryptic crossnumbers
partitions
coins
complex numbers
crosswords
elections
balancing
powers
christmas
neighbours
calculus
factorials
logic
colouring
angles
sum to infinity
quadrilaterals
decahedra
triangle numbers
addition
polynomials
grids
consecutive numbers
number
probabilty
integration
dice
division
fractions
axes
percentages
sums
albgebra
star numbers
lines
xor
crossnumbers
binary
digital clocks
multiplication
multiplaction squares
rectangles
prime factors
chalkdust crossnumber
sequences
cube numbers
perfect numbers
speed
shapes
pentagons
circles
sport
routes
floors
ave
bases
sets
coordinates
wordplay
3d shapes
integers
advent
hexagons
algebra
ellipses
multiples
cubics
gerrymandering
tournaments
quadratics
median
chess
means
dominos
geometric means
books
expansions
dates
people maths
combinatorics
chocolate
symmetry
graphs
mean
time
surds
medians
consecutive integers
square roots
proportion
square numbers
unit fractions
matrices
remainders
games
volume
doubling
area
perimeter
2d shapes
probability
tiling
square grids
products
cards
arrows
regular shapes
palindromes
trigonometry
spheres
geometry
menace
range
clocks
scales
the only crossnumber
lists
dodecagons
even numbers
rugby
differentiation
averages
indices
tangents
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
calculus
dice
integers
neighbours
cube numbers
rectangles
median
parabolas
logic
prime numbers
digital products
range
cryptic crossnumbers
factorials
expansions
sequences
coordinates
taxicab geometry
geometry
pascal's triangle
consecutive numbers
number
functions
sum to infinity
star numbers
prime factors
floors
coins
dominos
probabilty
2d shapes
irreducible numbers
odd numbers
spheres
trigonometry
unit fractions
symmetry
advent
sums
shape
graphs
polynomials
wordplay
multiplaction squares
bases
consecutive integers
hexagons
the only crossnumber
multiples
geometric means
lines
quadrilaterals
addition
albgebra
elections
partitions
triangles
dates
lists
polygons
doubling
algebra
factors
christmas
scales
remainders
square roots
rugby
axes
square numbers
quadratics
tournaments
games
digits
circles
cryptic clues
chocolate
integration
decahedra
numbers
complex numbers
determinants
angles
matrices
powers
sets
gerrymandering
grids
3d shapes
pentagons
shapes
squares
regular shapes
crossnumbers
dodecagons
multiplication
square grids
palindromes
triangle numbers
means
colouring
chalkdust crossnumber
books
speed
people maths
binary
indices
surds
sport
ellipses
fractions
digital clocks
time
arrows
balancing
geometric mean
xor
cubics
proportion
menace
percentages
chess
volume
averages
money
differentiation
perfect numbers
mean
ave
folding tube maps
planes
medians
combinatorics
probability
tangents
tiling
area
crosswords
clocks
even numbers
perimeter
cards
division
products
routes
© Matthew Scroggs 2012–2026