In a game of a snake and a ladder, the snake is to move exactly 35 steps. If the number of steps the snake takes at any point up the ladder is determined by a fair six-sided die such that if the number shown on the die is
, the snake takes
steps up the ladder.
In how many ways can the snake reach its destination?
Inspired by The snake and a ladder .
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using generating functions it is a simple one-liner in Mathematica
To break it down, after t throws of the die, the number of ways of arriving at step n is given by the expansion of (x+x^2+x^3+x^4+x^5+x^6)^t
After 35 moves he is going to be on or past step step 35, then we need to sum the above for t=1 to 35. After that we simply find the coefficient of x^35.