cp's OEIS Frontend

A075481 Number of iteration that first becomes smaller than the initial value if Collatz-function (A006370) is iterated, starting with numbers of form 64n+47. Corresponds to selection of every 16th term from A074474.

%I A075481 #6 Oct 15 2013 22:31:31
%S A075481 89,51,14,33,22,17,14,45,27,22,14,35,17,20,14,35,22,22,14,43,22,17,14,
%T A075481 27,128,20,14,25,17,25,14,20,22,30,14,82,20,17,14,45,22,27,14,25,17,
%U A075481 27,14,48,20,30,14,43,30,17,14,58,61,27,14,53,17,56,14,22,30,58,14,27,53
%N A075481 Number of iteration that first becomes smaller than the initial value if Collatz-function (A006370) is iterated, starting with numbers of form 64n+47. Corresponds to selection of every 16th term from A074474.
%C A075481 Remark that initial values of form 64m+r, if r={3,11,19,27,35,43,51,55} provide first-sink-lengths {7,9,7,9,7,9,7,9} respectively; e.g. {64k+19,192k+58,96k+29,288k+88,144k+44,72k+22,36k+11} submerge first below initial value at the 7th term,36k+11<64k+19.
%F A075481 a(n)=A075473[64n+47], n=0, ..., 256
%e A075481 n=2: 64n+47=175,list={175,526,263,790,395,1186,593,1780, 890,445,1336,668,334,167,502,251....}, i.e. the 14th term=167 is the first that <175, the initial value, so a(2)=14.
%Y A075481 Cf. A074473, A074474, A075476-A075483, A006370.
%K A075481 nonn
%O A075481 0,1
%A A075481 _Labos Elemer_, Sep 23 2002