“wel een normale wiskundige opgave” — Gathering of Tweakers

URL: https://gathering.tweakers.net/forum/list_messages/41508

Material: Exact question, discussion, multiple derivations and confirmed final answer.

The thread reproduces the crystal question, links its missing illustration directly to Hoeflin’s hosted material, and subsequently gives two complete summation derivations plus the final result. Match: exact. Exposure confidence: high. Correctness confidence: high.