Template:Sequence of the Day for May 23

Intended for: May 23, 2013

Timetable

• First draft entered by Alonso del Arte on April 27, 2012 ✓
• Draft reviewed by Daniel Forgues on August 27, 2012; May 22, 2015 ✓
• Draft to be approved by April 23, 2013

Yesterday's SOTD * Tomorrow's SOTD

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A083876: Smallest Fermat pseudoprime to bases 2 through

n

th prime

pn

.

{ 341, 1105, 1729, 29341, 29341, 162401, 252601, ... }

One of the less heralded properties of 1729 is that it is pseudoprime to bases 2, 3 and 5. However, it is not pseudoprime to base 7. There are numbers smaller than 1729 that are pseudoprime to base 7 and also to some other smaller bases, but the smallest pseudoprime to bases 2, 3, 5 and 7 is 29341 (which, quite coincidentally, has its three least significant digits in decimal equal to the smallest base 2 pseudoprime).