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%I #12 Sep 20 2016 03:04:48
%S 0,11,13,101,107,177,357,1001,1011,10759,11487,42189,113183,344253,
%T 1851759,4787769,15848679,139367847,240889077
%N Where records occur in A209252.
%C Except for the first term, all terms are coprime to 10. - _Chai Wah Wu_, Sep 19 2016
%p with(numtheory): P:= proc(q) local d,j,k,n,t,x; x:=4; print(0);
%p for n from 1 to q do d:=ilog10(n)+1; t:=0;
%p for k from 0 to d-1 do for j from 0 to 9 do
%p if isprime(trunc(n/10^(k+1))*10^(k+1)+j*10^k+(n mod 10^k))
%p then t:=t+1; fi; od; od;
%p if isprime(n) then if t-d>x then x:=t-d; print(n); fi; else
%p if t>x then x:=t; print(n); fi; fi; od; end: P(10^9);
%Y Cf. A000040, A209252.
%K nonn,base,more
%O 1,2
%A _Paolo P. Lava_, Sep 14 2016
%E a(18)-a(19) from _Chai Wah Wu_, Sep 19 2016
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