MathCastle
Proof WritingChallengeInduction

Induction · Challenge problem

In a take-away game, a player may remove 11, 33 or 44 stones; whoever takes the last stone wins. Strong induction on the pile size classifies every position. For how many starting piles nn with 1≤n≤1001 \le n \le 100 does the player to move LOSE?