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 2020

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

List of all puzzles


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


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2021