def len = 100
boolean [] arr = new boolean[len]
len.times{arr[it]=true;}
arr[0] = false;//Fill 1, arr[1] =3

//arr.eachWithIndex{v,k ->println v; println k*2+1 }

def times = Math.sqrt(len) + 2 
for(def i = 1; i < times; i++){
def j = i;
def dist = i+i+1;
j += dist;
for(; j < len; j=dist+j){
arr[ j ] = false;
}
//arr.eachWithIndex{v,k ->println v; println k*2+1 }
}
arr.eachWithIndex{v,i->if(v){ println i*2+1 + ", "}  }