Task

Write a boolean function that tells whether a given integer is prime.



Remember that   1   and all non-positive numbers are not prime.

Use trial division.

Even numbers greater than   2   may be eliminated right away.

A loop from   3   to   √ n    will suffice,   but other loops are allowed.



Related tasks

   count in factors
   prime decomposition
   AKS test for primes
   factors of an integer
   Sieve of Eratosthenes
   factors of a Mersenne number
   trial factoring of a Mersenne number
   partition an integer X into N primes
   sequence of primes by Trial Division


isprme(n):= catch(
  for k: 2 thru sqrt(n) do if mod(n, k)=0 then throw(false),
  true);
 
map(isprme, [2, 3, 4, 65, 100, 181, 901]);
/* [true, true, false, false, false, true, false] */