Star of David theorem

The Star of David theorem is a mathematical result on arithmetic properties of binomial coefficients. It was discovered by H.W. Gould in 1972.

Contents

Statement

The greatest common divisors of binomial coefficients forming the Star of David shape in Pascal's triangle, are equal:


\begin{align}
& {} \quad \gcd\left\{ \binom{n-1}{k-1}, \binom{n}{k%2B1}, \binom{n%2B1}{k}\right\} \\[8pt]
& = \gcd\left\{ \binom{n-1}{k}, \binom{n}{k-1}, \binom{n%2B1}{k%2B1}\right\}. 
\end{align}

See also

References

External links