Series Expansion of Differential Operators
122341
Exponential of a Differential Operator
123286
Taylor series for unitary operator in Weinberg
72427
Series expansion for small ratio of variables
21142
$\sum_{k=0} ^\infty (-1)^k \frac{(2k)!!}{(2k+1)!!} a^{2k+1}$ to differential equation
144551
Exercise on infinite series: pointwise product between convergent serie and unbounded sequence
140098
Laurent series expansion
49284
Solving an ODE in power series
112517
Proving bounds of a harmonic series
56429
Extension of partial derivatives and the definition of $C^k(\overline{\Omega})$
68212
Convergent series whose Cauchy product diverges
59165
Derivative of a linear transformation.
138784
Is the differentiation operator an open mapping?
59235
Finding eigenvalues of a differential operator
89185
The notation for partial derivatives
149895
A more convenient Fourier series
79196
Integrability of the Hilbert transform of a Schwartz function
119243
Taylor Series Expansion of $\frac{1}{\sin 2x}$ and $\frac{1}{1-e^{-x}}$