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A117272 Prime numbers p for which none of its digits appear in the decimal expansion of p/pi(p). 0

%I

%S 3,5,11,19,47,61,71,97,157,179,229,373,409,691,1231,1373,1987,2213,

%T 2557,3119,3989,8443,9311,17191,20707,26261,38281,41381,48611,54541,

%U 66889,74257,255709

%N Prime numbers p for which none of its digits appear in the decimal expansion of p/pi(p).

%e 373 is in the sequence because 1) it is a prime number, 2) there are 74 prime numbers smaller than or equal to 373, 3) in the decimal expansion of 373/74=5.04(054)... there are no 3's and 7's.

%t fQ[n_] := Block[{p = Prime@n}, Intersection[ Union@ Flatten@ RealDigits[p/n][[1]], IntegerDigits@ p] == {}]; Do[ If[fQ@n, Print@ Prime@n], {n, 200000}] (* _Robert G. Wilson v_ *)

%Y Cf. A000720: pi(n), the number of primes <= n.

%K base,more,nonn

%O 1,1

%A Luc Stevens (lms022(AT)yahoo.com), Apr 23 2006

%E Edited, corrected and extended by _Robert G. Wilson v_, Apr 24 2006

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Last modified September 21 03:45 EDT 2020. Contains 337266 sequences. (Running on oeis4.)