with javascript_semantics
atom t0 = time()
function totient(integer n)
    integer tot = n, i = 2
    while i*i<=n do
        if mod(n,i)=0 then
            while true do
                n /= i
                if mod(n,i)!=0 then exit end if
            end while
            tot -= tot/i
        end if
        i += iff(i=2?1:2)
    end while
    if n>1 then
        tot -= tot/n
    end if
    return tot
end function

printf(1," n  phi   prime\n")
printf(1," --------------\n")
for n=1 to 25 do
    integer tot = totient(n)
    bool prime = (n-1=tot)
    printf(1,"%2d   %2d   %t\n",{n,tot,prime})
end for
printf(1,"\n")
integer count = 0
for n=1 to 1e6 do
--  count += (totient(n)=n-1)
    count += (phi(n)=n-1)
    if find(n,{25,1e2,1e3,1e4,1e5,1e6,1e7}) then
        printf(1,"Number of primes up to %d = %d\n",{n,count})
    end if
end for
?elapsed(time()-t0)