Solution to problem 46 in Julia

src/Julia/Problem046.jl

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+#=
+Created on 16 Sep 2021
+
+@author: David Doblas Jiménez
+@email: daviddoji@pm.me
+
+Solution for Problem 46 of Project Euler
+https://projecteuler.net/problem=46
+=#
+
+using BenchmarkTools
+using Primes
+
+function is_goldbach(number)
+    for i in number - 1:-1:1
+        if isprime(i) & ((((number - i) / 2)^0.5)%1==0)
+            return true
+        end
+    end
+    return false
+end
+
+function Problem46()
+    #=
+    It was proposed by Christian Goldbach that every odd composite number 
+    can be written as the sum of a prime and twice a square.
+
+    9 = 7 + 2×1^2
+    15 = 7 + 2×2^2
+    21 = 3 + 2×3^2
+    25 = 7 + 2×3^2
+    27 = 19 + 2×2^2
+    33 = 31 + 2×1^2
+
+    It turns out that the conjecture was false.
+
+    What is the smallest odd composite that cannot be written as the sum 
+    of a prime and twice a square?
+    =#
+    ans = 9
+    while true
+        ans += 2
+        if !isprime(ans) & !is_goldbach(ans)
+            return ans
+        end
+    end
+end
+
+
+println("Time to evaluate Problem 46:")
+@btime Problem46()
+println("")
+println("Result for Problem 46: ", Problem46())