Square Cullen Numbers
Jump to navigation
Jump to search
Theorem
The numbers:
- $1, 9, 25$
are Cullen numbers which are also square.
Proof
We have:
\(\ds 1\) | \(=\) | \(\ds 0 \times 2^0 + 1\) | ||||||||||||
\(\ds 9\) | \(=\) | \(\ds 2 \times 2^2 + 1\) | ||||||||||||
\(\ds 25\) | \(=\) | \(\ds 3 \times 2^3 + 1\) |
$\blacksquare$
Sources
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $25$