cp's OEIS Frontend

A076182 a(n) = A006666(n) mod 2.

%I A076182 #16 Aug 14 2017 05:25:54
%S A076182 0,1,1,0,0,0,1,1,1,1,0,1,1,0,0,0,1,0,0,0,0,1,1,0,0,0,0,1,1,1,1,1,0,0,
%T A076182 0,1,1,1,1,1,1,1,0,0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,1,1,1,1,
%U A076182 1,1,1,0,1,0,1,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,0,1,0,0,0,0,0,0,0,0
%N A076182 a(n) = A006666(n) mod 2.
%H A076182 Antti Karttunen, <a href="/A076182/b076182.txt">Table of n, a(n) for n = 1..10000</a>
%H A076182 <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a>
%H A076182 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F A076182 a(n) = A006513(n) - 1.
%F A076182 Apparently also the antiparity of A064433. - _Ralf Stephan_, Nov 16 2004
%o A076182 (PARI) a(n)=if(n<0,0,s=n; c=0; while(s>1,s=(s%2)*(3*s+1)/2+(1-s%2)*s/2; c++); c)%2
%o A076182 (Scheme)
%o A076182 (define (A076182 n) (modulo (A006666 n) 2))
%o A076182 (definec (A006666 n) (if (= 1 n) 0 (+ 1 (A006666 (A014682 n))))) ;; With memoization-macro definec
%o A076182 (define (A014682 n) (if (even? n) (/ n 2) (/ (+ n n n 1) 2)))
%o A076182 ;; _Antti Karttunen_, Aug 13 2017
%Y A076182 Cf. A014682, A006513, A006666, A076092.
%K A076182 nonn
%O A076182 1,1
%A A076182 _Benoit Cloitre_, Nov 01 2002