A107465 Numbers k such that 10^k*(66161819199+10^(k+10)) + 1 is prime.

3, 32, 96, 104, 603, 870, 1609, 2505, 4889, 5024, 5345, 14955

Offset: 1

Author

Jason Earls, May 27 2005

Keywords

• base
• nonn
• more

Comments

These are non-palindromic strobogrammatic primes and they have all been certified. No more terms up to 8700. Primality proof for the largest (a "gigantic" prime): PFGW Version 20041001.Win_Stable (v1.2 RC1b) [FFT v23.8] Primality testing 10^5345*(66161819199+10^(5345+10))+1 [N-1, Brillhart-Lehmer-Selfridge] Running N-1 test using base 3 Calling Brillhart-Lehmer-Selfridge with factored part 34.91% 10^5345*(66161819199+10^(5345+10))+1 is prime! (15.1367s+0.0109s)

Links

• R. Ondrejka, The Top Ten: a Catalogue of Primal Configurations.

Crossrefs

Cf. A007597.

Programs

PARI

is(n)=ispseudoprime(10^n*(66161819199+10^(n+10))+1) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(12) from Michael S. Branicky, Sep 21 2024