NL-NWO 1983 Problem 2

Prove that if $n$ is an odd positive integer, then the last two digits of $2^{2n}(2^{2n+1}-1)$ in base $10$ are $28$ .

Dataset text AI-MO AoPS. Quoted with source.

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.