Search: id:A096246
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%I A096246
%S A096246 2,3,5,7,11,13,19,23,29,37,43,47,53,59,61,73,79,83,101,107,109,137,149,
%T A096246 151,157,163,167,173,179,197,211,229,277,281,293,307,311,313,317,331,
%U A096246 347,349,359,389,397,419,421,457,461,467,557,563,569,587,599,601,613
%N A096246 Base-2 deletable primes (written in base 10).
%C A096246 A prime p is a base-b deletable prime if when written in base b it has 
               the property that removing some digit leaves either the empty string 
               or another deletable prime. However, in base 2 we adopt the convention 
               that 2 = 10 and 3 = 11 are deletable.
%C A096246 Deleting a digit cannot leave any leading zeros in the new string. For 
               example, deleting the 2 in 2003 to obtain 003 is not allowed.
%p A096246 isDel := proc(n::integer) local b2,redu,rpr,d; if n = 2 or n =3 then 
               RETURN(true); elif not isprime(n) then RETURN(false); else b2 := 
               convert(n,base,2); for d from 1 to nops(b2) do redu := [op(1..d-1,
               b2),op(d+1..nops(b2),b2) ]; if op(nops(redu),redu) = 1 then rpr := 
               sum( op(i,redu)*2^(i-1),i=1..nops(redu)); if isDel(rpr) then RETURN(true); 
               fi; fi; od; RETURN(false); fi; end: for n from 1 to 200 do if isDel(ithprime(n)) 
               then printf("%d,",ithprime(n)); fi; od: - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Apr 25 2006
%Y A096246 Cf. A080608, A080603, A096235-A096245.
%Y A096246 Sequence in context: A005728 A049643 A050437 this_sequence A106639 A078334 
               A108696
%Y A096246 Adjacent sequences: A096243 A096244 A096245 this_sequence A096247 A096248 
               A096249
%K A096246 nonn
%O A096246 1,1
%A A096246 Michael Kleber (michael.kleber(AT)gmail.com), Feb 28 2003
%E A096246 More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 25 2006

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