A127003 Smallest prime p such that p+10^n is also prime.

2, 3, 3, 13, 7, 3, 3, 19, 7, 7, 19, 3, 61, 37, 31, 37, 61, 3, 3, 97, 151, 193, 139, 157, 7, 13, 67, 103, 331, 379, 211, 271, 709, 61, 193, 103, 67, 43, 547, 3, 139, 109, 991, 79, 31, 439, 937, 193, 193, 2089, 151, 457, 919, 223, 31, 157, 3, 607, 601, 19, 7, 379, 991, 307

Offset

0,1

Links

Pierre CAMI, Table of n, a(n) for n = 0..1000

Example

a(3)=13 because 13 is the smallest prime p such that p+10^3 (=1013) is also prime: For the primes < 13, 1002=2*3*167, 1003=17*59, 1005=3*5*67, 1007=19*53 and 1011=3*337, respectively, are not prime.

Mathematica

s={}; Do[p=0; Until[PrimeQ[Prime[p]+10^n], p++]; AppendTo[s, Prime[p]], {n, 0, 63}]; s (* James C. McMahon, Dec 29 2024 *)

Crossrefs

Cf. A127004, A056206.

Sequence in context: A196837 A275212 A370554 * A211673 A184178 A350531

Adjacent sequences: A127000 A127001 A127002 * A127004 A127005 A127006

Keyword

nonn

Author

Rick L. Shepherd, Jan 01 2007

Status

approved