A070854 Smallest prime == 1 mod (10^n).

11, 101, 3001, 70001, 700001, 22000001, 30000001, 600000001, 6000000001, 30000000001, 1900000000001, 18000000000001, 40000000000001, 3900000000000001, 6000000000000001, 130000000000000001, 3700000000000000001, 15000000000000000001, 150000000000000000001, 600000000000000000001, 16000000000000000000001

Offset: 1

Author

Amarnath Murthy, May 15 2002

Keywords

• nonn

Comments

a(6) through a(21) have been certified prime with Primo. - Rick L. Shepherd, Jun 03 2002

Crossrefs

Cf. A070846 to A070853.

Programs

PARI

a(n)=for(i=1,+oo,if(isprime(i*10^n+1), return(i*10^n+1))) \\ Johann Peters, Dec 27 2024

Formula

a(n) = A121172(n)*10^n + 1. - Ray Chandler, Feb 10 2009

Extensions

More terms from Rick L. Shepherd, Jun 03 2002