\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.7}
\begin{document}
\begin{tikzpicture}[
declare function={binom(\k,\n,\p)=\n!/(\k!*(\n-\k)!)*\p^\k*(1-\p)^(\n-\k);}
]
\begin{axis}[
axis lines=middle,
samples at={300,...,500},
xmin=0, xmax=2000,
xtick={0,500,...,2000},
xticklabels={0,500,...,2000},
minor xtick={0,100,...,2000},
extra x ticks={0}, % Origo
y tick label style={
/pgf/number format/.cd,
fixed,
fixed zerofill,
precision=1,