When are the sum of the digits of $2^n$ and $2^{n+1}$ equal and for what value of n? Stuck on this problem!
108497
Can $2^n$ and $2^{n+1}$ have the same digit sum?
111098
Prove $2^{2n} = \sum_{k=0}^{n}\binom{2n+1}{k}$
126124
Why is the sum of the digits in a multiple of 9 also a multiple of 9?
78632
Summation equation for $2^{x-1}$
2678
Values of $\sum_{n=0}^\infty x^n$ and $\sum_{n=0}^N x^n$
110722
$n$ and $n^5$ have the same units digit?
43903
Find the sum for $\sum_{n=1}^{\infty}(-1)^{(n+1)}\frac{2n+1}{3^n} $
33082
Proving $\sum_{i=0}^n 2^i=2^{n+1}-1$ by induction.
3798
Finding formula for sum $S_n = \sum_{i=1}^n i(i-1)$
147485
A conjecture about numbers of the form $10^{m}(2^{k}−1)+2^{k-1}−1$, where $m$ is the number of decimal digits of $ 2^{k-1}$.
131708
Sum of powers of natural numbers
9302
Questions about Divisibility of $2^n$ by $3$
72437
Sum of the digits of a perfect square
13677
Sum of digits of repunits
147910
Prove that $\sum_{n=0}^N\binom{2N-n}N2^n(n+1)=(1+2N)\binom{2N}N$
10777
Proof of the identity $2^n = \sum\limits_{k=0}^n 2^{-k} \binom{n+k}{k}$
80177
Sum from $n=1$ to $N$ of $\sin(nx)/2^n$