So here's a code in perl to find nth prime number.

#!/usr/bin/perl

print "Enter the number: ";

chomp($num = <>);

$i = 3;

$no_of_prime = 3;

$prime = 0;

if ($num == 1)

{

print "1st prime is 2 \n";

}

elsif ($num == 2)

{

print "2nd prime is 3 \n";

}

elsif ($num > 2)

{

$index = 1;

$powindex = 1;

$no_of_prime = 2;

while($no_of_prime < $num)

{

$prime = (6 * $index) + ((-1) ** $powindex);

$j = 2;

$is_prime = 1;

while($j <= ($prime ** 0.5))

{

if(($prime % $j) == 0)

{

$is_prime = 0;

break;

}

$j = $j + 1;

}

if ($is_prime == 1)

{

$no_of_prime++;

}

if(($powindex % 2) == 0)

{

$index = $index + 1;

}

$powindex = $powindex + 1;

}

print $num, "th prime is: ", $prime, "\n";

}

else

{

print "Invalid number\n";

}

#END

#!/usr/bin/perl

print "Enter the number: ";

chomp($num = <>);

$i = 3;

$no_of_prime = 3;

$prime = 0;

if ($num == 1)

{

print "1st prime is 2 \n";

}

elsif ($num == 2)

{

print "2nd prime is 3 \n";

}

elsif ($num > 2)

{

$index = 1;

$powindex = 1;

$no_of_prime = 2;

while($no_of_prime < $num)

{

$prime = (6 * $index) + ((-1) ** $powindex);

$j = 2;

$is_prime = 1;

while($j <= ($prime ** 0.5))

{

if(($prime % $j) == 0)

{

$is_prime = 0;

break;

}

$j = $j + 1;

}

if ($is_prime == 1)

{

$no_of_prime++;

}

if(($powindex % 2) == 0)

{

$index = $index + 1;

}

$powindex = $powindex + 1;

}

print $num, "th prime is: ", $prime, "\n";

}

else

{

print "Invalid number\n";

}

#END