“An inebriated person in Nice (see Figure 1) takes a walk, each step in one of the four cardinal directions, north (N), south (S), east (E), and west (W). We are interested in those walks beginning at the center of the Promenade des Anglais (at the southern end of town) and ending anywhere on the promenade—all the while remaining on land (in other words, not venturing south of the promenade). In how many possible ways can such walks meander?”
For a detailed mathematical solution to this problem, see: ‘Touchard’s Drunkard’ by professor Nachum Dershowitz, School of Computer Science Tel Aviv University, Israel, in the Journal of Integer Sequences, Volume 20, 2017, Issue 1.
[ Research research by Martin Gardiner ]