A216347 Primes of the form k*10^k + 1.

11, 3001, 9000000001, 21000000000000000000001

Offset

1,1

Comments

The corresponding k are in A007647.

a(5) = 363000000...00001 contains 366 digits.

Links

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

Mathematica

lst={}; Do[ p=n*10^n+ 1; If[PrimeQ[p], AppendTo[lst, p]], {n, 0, 21}]; lst
Select[Table[n*10^n+1, {n, 40}], PrimeQ] (* Harvey P. Dale, Jul 18 2020 *)

Crossrefs

Cf. A007647.

Sequence in context: A222315 A185556 A227785 * A377762 A214137 A295192

Adjacent sequences: A216344 A216345 A216346 * A216348 A216349 A216350

Keyword

nonn

Author

Michel Lagneau, Sep 04 2012

Status

approved