A233385 Primes that are a concatenations of n-th Mersenne exponent and n-th Mersenne prime.

23, 37, 7127, 138191, 19524287

Offset

1,1

Comments

Primes of the form A000043(n)*10^A028335(n) + A000668(n).

Links

Table of n, a(n) for n=1..5.

Example

a(4) is 138191(prime number) where 13 is 5th Mersenne exponent and 8191 is 5th Mersenne prime.

Mathematica

Select[Table[With[{m=MersennePrimeExponent[n]}, {c=2^m-1}, m*10^IntegerLength[c]+c], {n, 20}], PrimeQ] (* Harvey P. Dale, Feb 07 2026 *)

Crossrefs

Cf. A000043, A000668, A028335.

Sequence in context: A089782 A113893 A146390 * A282712 A134754 A134755

Adjacent sequences: A233382 A233383 A233384 * A233386 A233387 A233388

Keyword

nonn,base,less

Author

Juri-Stepan Gerasimov, Dec 08 2013

Status

approved