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

Author

Rick L. Shepherd, Jan 01 2007

Keywords

• nonn

Examples

			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.
		

Links

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

Crossrefs

Cf. A127004, A056206.

Programs

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 *)