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A372362 a(n) is the 2-adic valuation of 1 + 3*{the n-th iterate of 27 with Reduced Collatz-function R}.

%I A372362 #6 May 06 2024 14:33:59
%S A372362 1,2,1,1,1,1,2,2,1,2,1,1,2,1,1,1,2,3,1,1,2,1,2,1,1,1,1,1,3,1,1,1,4,2,
%T A372362 2,4,3,1,1,5,4,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
%U A372362 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2
%N A372362 a(n) is the 2-adic valuation of 1 + 3*{the n-th iterate of 27 with Reduced Collatz-function R}.
%H A372362 <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a>
%F A372362 a(n) = A371093(A372443(n)).
%o A372362 (PARI)
%o A372362 A000265(n) = (n>>valuation(n,2));
%o A372362 A371093(n) = valuation(1+3*n,2);
%o A372362 A372443(n) = { my(x=27); while(n, x=A000265(3*x+1); n--); (x); };
%o A372362 A372362(n) = A371093(A372443(n));
%Y A372362 Cf. A371093, A372443, A372447, A372448.
%Y A372362 The first 41 terms form the row 13 of A351122.
%K A372362 nonn
%O A372362 0,2
%A A372362 _Antti Karttunen_, May 06 2024