login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Numbers m such that all 11 numbers 10^k*m+1; k=0,1,...,9 & 10 are prime.
2

%I #6 Jul 06 2022 10:05:17

%S 89468493268,342174928102,1124855005456,1183450662310,1885504856592,

%T 2425861640748,2926121345812,3713879215312,3984048347706,

%U 4181062989166,4335021717418,5232993739512,6009549731752,6406772991528,7451945623752,8329610667490,8533933744882,9374871820930,9425264464140,9578838492160

%N Numbers m such that all 11 numbers 10^k*m+1; k=0,1,...,9 & 10 are prime.

%C If m & n are in the sequence, k<11 and r=m*n*10^k -1 is prime then r has at least k+1 representations of the form p*q-(p+q)where p & q are prime.

%H Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_482.htm">Two Bergot questions</a>

%Y Cf. A153431, A153432.

%K nonn

%O 1,1

%A _Farideh Firoozbakht_, Apr 02 2009

%E A153433 a(3)-a(20) from _Don Reble_, Jul 06 2022