An apparent 67.
#000000001111111111222222222233333333334444444444555555555566666666
#234567890123456789012345678901234567890123456789012345678901234567
$i=43;$p=1;eval'$x'.chr($i).'=4/$p;$p+=2;$i^=6'for 1..10**5;print$x
update :
#0000000011111111112222222222333333333344444444445555555555
#2345678901234567890123456789012345678901234567890123456789
$o=1;$t=3;for(1..1e5){$e+=(4/$o)-(4/$t);$o+=4;$t+=4}print$e
Simplify, simplify... :)
update :
to Chmrr : (1**5) yeah, I saw that in another solution and felt rather sheepish. As to the exact value of the number, I felt it appropriate to use something approximate to Ovid's original algorithm.