I am no great mathematician but I haven't seen a mathematical description of Martindale on your site.

Martindale is a gambling technique wherebye you double your wager every time you lose, when you win you go back to your normal wager.

This is a Geometric progression with a multiplier of two, this particular multiplier is required as a win will recover all previous losses.
If the multiplier isn't TWO it isn't Martindale.

If 'a' is your initial wager
If 'r' is the multiplier ( for Martindale =2)
If 'n' is the number of terms ( losses) in the series

Sum = a+a*r + a*r^2+a*r^3+a*r^4+a*r^5 +...........a*r^(n-1)

Sum= a (1-r^n)/(1-r)

eg If a=$10
n=7

Sum = 10(1-2^7)/(1-2)

Sum = $1,270