A recursive solution: 
sub c {
    my$a=pop;$a==1?1:8**($a-1)+c($a-1)
}

[download]
And a non-recursive one: 
sub c {
    my$a=1;$a+=8**$_ for(1..pop-1);$a
}

[download]
updates on that last bit of code
Dr. Michael K. Neylon - mneylon-pm@masemware.com || "You've left the lens cap of your mind on again, Pinky" - The Brain

In reply to Re: Intriguing problem; maybe golf? by Masem
in thread Intriguing problem; maybe golf? by Anonymous Monk

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