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%I #23 May 10 2014 09:55:16
%S 13,17,23,37,43,47,53,67,73,83,97,103,107,113,131,137,167,173,179,197,
%T 211,223,229,241,271,283,307,311,313,317,331,337,347,353,359,367,373,
%U 379,383,389,397,419,431,443,461,467,479,503,523,541,547,571,607,613,617
%N Primes that remain prime when the leftmost digit is removed.
%H K. D. Bajpai, <a href="/A227916/b227916.txt">Table of n, a(n) for n = 1..10000</a>
%e a(11)= 97 which is prime. Removing the leftmost digit gives 7, also prime.
%e a(28)= 311 which is prime. Removing the leftmost digit gives 11, also prime.
%p KD:= proc() local a,b,c,d; a:=ithprime(n);b:=length(a); c:=floor(a/(10^(b-1)));d:=a-c*(10^(b-1));if isprime(d) then return(a):fi; end:seq(KD(),n=1..5000);
%Y Cf. A000040 (prime numbers), A024785 (left-truncatable primes).
%Y Cf. A137812 (left- or right-truncatable primes).
%Y Cf. A227919 (primes which remain prime when rightmost digit is removed).
%K nonn,base
%O 1,1
%A _K. D. Bajpai_, Oct 13 2013
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