4 ms·
http://www.wolframalpha.com/input/?i=1%2F2++%286+n-cos%28pi+n%29%2B3%29 http://www.wolframalpha.com/input/?i=1%2F2++%286+n-cos%28pi+...
by stillbourne 11y ago
http://www.wolframalpha.com/input/?i=1%2F2++%286+n-cos%28pi+n%29%2B3%29 http://www.wolframalpha.com/input/?i=1%2F2++%286+n-cos%28pi+...