Heads or tails
Infinitely many coins coins are aligned, with heads facing up.
1 – Then, all coins are flipped.
2- Then, the second, fourth, sixth, … are flipped.
3- Then, the third, sixth, ninth,… are flipped.
k- Then, coins numbered k, 2k, 3k, … are flipped.
After this infinite process is done, what is the proportion of the coins numbered p, p^2, p^3, p^4, … that will be facing heads (where p>1 is an integer) ?