%I A087381
%S A087381 1,1,1,0,1,0,1,0,0,10,11,11,11,10,11,10,11,10,10,10,11,11,11,10,11,10,
%T A087381 11,10,10,10,11,11,11,10,11,10,11,10,10,0,1,1,1,0,1,0,1,0,0,10,11,11,11,
%U A087381 10,11,10,11,10,10,0,1,1,1,0,1,0,1,0,0,10,11,11,11,10,11,10,11,10,10,0
%N A087381 Let Compri(n) be the number obtained by replacing each prime digit (2,
               3,5,7) of n by a '1' and a composite digit( 0,4,6,8,9) by a '0' . 
               A 1 remains the same. a(n) = Compri(n).
%C A087381 For all numbers using only composite digits( 0,4,6,8,9,) a(n) = 0. For 
               a 'k' digit number using 1 and/or only prime digits a(n) = (10^k-1)/
               9.
%e A087381 a(4206) = 100
%e A087381 a(10235479) = 10111010
%Y A087381 Cf. A087380.
%Y A087381 Sequence in context: A077812 A004288 A065016 this_sequence A136400 A121266 
               A045988
%Y A087381 Adjacent sequences: A087378 A087379 A087380 this_sequence A087382 A087383 
               A087384
%K A087381 base,nonn
%O A087381 1,10
%A A087381 Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 09 2003
%E A087381 More terms from David Wasserman (wasserma(AT)spawar.navy.mil), May 25 
               2005