Euler problems/171 to 180
Finding numbers for which the sum of the squares of the digits is a square.
problem_171 = undefined
Investigating numbers with few repeated digits.
problem_172 = undefined
Using up to one million tiles how many different "hollow" square laminae can be formed? Solution:
problem_173= let c=div (10^6) 4 xm=floor$sqrt $fromIntegral c k=[div c x|x<-[1..xm]] in sum k-(div (xm*(xm+1)) 2)
Counting the number of "hollow" square laminae that can form one, two, three, ... distinct arrangements.
problem_174 = undefined
Fractions involving the number of different ways a number can be expressed as a sum of powers of 2. Solution:
problem_175 = undefined
Rectangular triangles that share a cathetus. Solution:
problem_176 = undefined
Integer angled Quadrilaterals.
problem_177 = undefined
Step Numbers Solution:
problem_178 = undefined
Consecutive positive divisors. Solution:
problem_179 = undefined
10 Problem 180
problem_180 = undefined