Numbers Appearing 8 Times in Pascal's Triangle
Jump to navigation
Jump to search
Theorem
Excluding $1$, the number $3003$ is the smallest integer to appear $8$ times in Pascal's triangle.
No other number below $2^{23}$ appears as often.
Proof
\(\ds 3003\) | \(=\) | \(\, \ds \frac {3003!} {3002! \times 1!} \, \) | \(\, \ds = \, \) | \(\ds \dbinom {3003} 1\) | ||||||||||
\(\ds \) | \(=\) | \(\, \ds \frac {78!} {76! \times 2!} \, \) | \(\, \ds = \, \) | \(\ds \dbinom {78} 2\) | ||||||||||
\(\ds \) | \(=\) | \(\, \ds \frac {15!} {10! \times 5!} \, \) | \(\, \ds = \, \) | \(\ds \dbinom {15} 5\) | ||||||||||
\(\ds \) | \(=\) | \(\, \ds \frac {14!} {8! \times 6!} \, \) | \(\, \ds = \, \) | \(\ds \dbinom {14} 6\) | ||||||||||
\(\ds \) | \(=\) | \(\, \ds \frac {14!} {6! \times 8!} \, \) | \(\, \ds = \, \) | \(\ds \dbinom {14} 8\) | ||||||||||
\(\ds \) | \(=\) | \(\, \ds \frac {15!} {5! \times 10!} \, \) | \(\, \ds = \, \) | \(\ds \dbinom {15} {10}\) | ||||||||||
\(\ds \) | \(=\) | \(\, \ds \frac {78!} {2! \times 76!} \, \) | \(\, \ds = \, \) | \(\ds \dbinom {78} {76}\) | ||||||||||
\(\ds \) | \(=\) | \(\, \ds \frac {3003!} {1! \times 3002!} \, \) | \(\, \ds = \, \) | \(\ds \dbinom {3003} {3002}\) |
![]() | This theorem requires a proof. In particular: It remains to be shown that there are no other occurrences of $3003$, and that there are no other numbers less than $2^{23}$ with this property. You can help $\mathsf{Pr} \infty \mathsf{fWiki}$ by crafting such a proof. To discuss this page in more detail, feel free to use the talk page. When this work has been completed, you may remove this instance of {{ProofWanted}} from the code.If you would welcome a second opinion as to whether your work is correct, add a call to {{Proofread}} the page. |
Also see
Sources
- Apr. 1971: David Singmaster: How Often Does an Integer Occur as a Binomial Coefficient? (Amer. Math. Monthly Vol. 78, no. 4: pp. 385 – 386) www.jstor.org/stable/2316907
- 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $3003$
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $3003$