%I A090421
%S A090421 2,3,5,7,11,13,15,17,19,21,23,29,31,37,41,43,45,47,53,55,59,61,63,67,71,
%T A090421 73,79,81,83,87,89,91,93,95,97,101,103,107,109,111,113,115,119,123,125,
%U A090421 127,131,137,139,141,143,149,151,157,159,163,165,167,169,171,173
%N A090421 Numbers that can be written in binary representation as concatenation 
               of primes.
%C A090421 A090418(a(n)) > 0; complement of A090419.
%Y A090421 Cf. A004676, A007088, A090420, A090422, A090423.
%Y A090421 Sequence in context: A095179 A074895 A072697 this_sequence A102553 A069161 
               A003277
%Y A090421 Adjacent sequences: A090418 A090419 A090420 this_sequence A090422 A090423 
               A090424
%K A090421 nonn,base
%O A090421 1,1
%A A090421 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 30 2003