Advent calendar 2018

11 December

Today's number is the number \(n\) such that $$\frac{216!\times215!\times214!\times...\times1!}{n!}$$ is a square number.

Show answer


Show me a random puzzle
 Most recent collections 

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

List of all puzzles


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


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2020