If $P$ is a polynomial of degree at most $N$, we have $$\sum_{n=0}^{N+1}P(n)(-1)^n\binom{N+1}{n}=0$$
I tried using pascal's identity $\binom{N+1}{n}=\binom{N}{n}+\binom{N}{n-1}$. I think that differences of polynomials might work.
If $P$ is a polynomial of degree at most $N$, we have $$\sum_{n=0}^{N+1}P(n)(-1)^n\binom{N+1}{n}=0$$
I tried using pascal's identity $\binom{N+1}{n}=\binom{N}{n}+\binom{N}{n-1}$. I think that differences of polynomials might work.