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A080608 Deletable primes: primes such that removing some digit leaves either the empty string or another deletable prime. 22

%I

%S 2,3,5,7,13,17,23,29,31,37,43,47,53,59,67,71,73,79,83,97,103,107,113,

%T 127,131,137,139,157,163,167,173,179,193,197,223,229,233,239,263,269,

%U 271,283,293,307,311,313,317,331,337,347,353,359,367,373,379,383,397,431,433,439

%N Deletable primes: primes such that removing some digit leaves either the empty string or another deletable prime.

%C Subsequence of A179336. [_Reinhard Zumkeller_, Jul 11 2010]

%H David W. Wilson, <a href="/A080608/b080608.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/DeletablePrime.html">Deletable Prime</a>

%p read("transforms"):

%p isA080608 := proc(n)

%p option remember;

%p local dgs,i ;

%p if isprime(n) then

%p if n < 10 then

%p true;

%p else

%p dgs := convert(n,base,10) ;

%p for i from 1 to nops(dgs) do

%p subsop(i=NULL,dgs) ;

%p digcatL(ListTools[Reverse](%)) ;

%p if procname(%) then

%p return true;

%p end if;

%p end do:

%p false ;

%p end if;

%p else

%p false;

%p end if;

%p end proc:

%p n := 1;

%p for i from 1 to 500 do

%p p := ithprime(i) ;

%p if isA080608(p) then

%p printf("%d %d\n",n,p) ;

%p n := n+1 ;

%p fi ;

%p end do: # _R. J. Mathar_, Oct 11 2014

%Y Cf. A080603, A096235-A096246.

%K nonn,easy,base

%O 1,1

%A _David W. Wilson_, Feb 25 2003

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Last modified December 11 19:09 EST 2017. Contains 295919 sequences.