A159264 - OEIS

%I #23 Jan 06 2025 15:11:52

%S 3,6,8,9,37,44,67,111,157,289,1256,1602,2410,2482,2868,3824,3891,6595,

%T 8984,9318,10274,45858,59152,86691,99952,110616,114735,213199

%N Numbers n such that 379*10^n+9 is a ("Google") probable prime.

%C The prime number 379009 rotated by 180 degree reads "GOOGLE". This sequence gives n such that "GO...OGLE" with n-1 O's is prime.

%D J. Earls, Mathematical Bliss, Pleroma Publications, 2009, pages 15-17. ASIN: B002ACVZ6O [From _Jason Earls_, Nov 21 2009]

%H Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=379*10^n%2B9&amp;action=Search">PRP Records</a>

%t Select[Range[3, 300], PrimeQ[379*10^# + 9] &] (* _Arkadiusz Wesolowski_, Oct 05 2011 *)

%o (PARI) for(n=0, oo, ispseudoprime(379*10^n+9) & print1(n", "))

%Y A159265 lists the actual primes.

%K nonn,hard,more

%O 1,1

%A _M. F. Hasler_, Apr 07 2009

%E a(22)-a(24) from _Arkadiusz Wesolowski_, Oct 15 2011

%E a(25)-a(28) from _Jason Yuen_, Jan 06 2025