A377465 Exponents of Mersenne primes that are emirps.

13, 17, 31, 107, 1279, 9941, 3021377, 13466917

Offset: 1

Author

Rodolfo Ruiz-Huidobro, Oct 29 2024

Keywords

• nonn
• base
• more

Comments

The just discovered Mersenne exponent 136279841 is also an emirp. However, it cannot be included as the next member of the sequence as there are Mersenne exponents over 70000000 that have not been double checked yet.

Examples

			107 is a term because it is in A000043 and in A006567.
		

Links

• Eric Weisstein's World of Mathematics, Emirp.
• Wikipedia, Emirp.

Crossrefs

Intersection of A000043 and A006567.

Programs

Mathematica

Select[MersennePrimeExponent[Range[48]], PrimeQ[p=FromDigits[Reverse[IntegerDigits[#]]]] && p!=# &] (* Stefano Spezia, Nov 02 2024 *)