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16 votes
6 answers
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A Leibniz-like formula for $(f(x) \frac{d}{dx})^n f(x)$?

Let $f(x)$ be sufficiently regular (e.g. a smooth function or a formal power series in characteristic 0 etc.). In my research the following recursion made a surprising entrance $$ f_1(x) = f(x),\ f_{n+...
M.G.'s user avatar
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2 votes
1 answer
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The combinatorics of $(f \partial)^n$ in the noncommutative setting?

This is a noncommutative version of these three previous questions: differential operator power coefficients Сlosed formula for $(g\partial)^n$ A Leibniz-like formula for $(f(x) \frac{d}{dx})^n f(x)$? ...
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