Search: id:A087381 Results 1-1 of 1 results found. %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 Search completed in 0.001 seconds