%I A036556
%S A036556 7,14,23,27,28,29,31,39,46,54,56,57,58,62,71,78,87,91,92,93,95,103,107,
%T A036556 108,109,111,112,113,114,115,116,117,119,123,124,125,127,135,142,151,
%U A036556 155,156,157,159,167,174,182,184,185,186,190,199,206,214
%N A036556 Integers which when multiplied by 3 have an odd number of 1's in their 
               binary expansion (cf. A000069).
%C A036556 In other words, numbers n such that 3n is odious.
%C A036556 Numbers n such that valuation(binomial(3n,n),2) is odd. - Benoit Cloitre 
               (benoit7848c(AT)orange.fr), Jun 06 2004
%C A036556 Intersection of A000069 and A008585 (multiples of 3), divided by 3.
%t A036556 Select[ Range[ 214 ], OddQ[ Plus@@IntegerDigits[ 3#, 2 ]]& ]
%o A036556 (PARI) for(n=1,214,if(valuation(binomial(3*n,n),2)%2==1,print1(n,",")))
%Y A036556 Cf. A000069, A036555-A036557.
%Y A036556 Sequence in context: A061823 A018890 A118502 this_sequence A013644 A050953 
               A025011
%Y A036556 Adjacent sequences: A036553 A036554 A036555 this_sequence A036557 A036558 
               A036559
%K A036556 nonn,base
%O A036556 1,1
%A A036556 Dan Hoey (Hoey(AT)AIC.NRL.Navy.Mil)
%E A036556 Definition corrected Jan 09 2007