A129377 - OEIS

%I #4 Mar 30 2012 17:31:22

%S 3,2,1,17,19,14,10,7,5,500,404,311,233,215,161,2363,1772,3097,11474,

%T 8605,8234,6175,4631,3473,34196,30779,23084,38752,422549,335165,

%U 1500443,1125332,2039653,2762863,2072147,1554110,1165582,874186,655639,491729

%N First occurrence of n in A085068.

%C A085068: Number of steps for iteration of map x -> (4/3)*ceiling(x) to reach an integer > n when started at n, or -1 if no such integer is ever reached.

%C In the creation of this sequence I have tested all integers from 0 to 400000000 and they all reach an integer.

%H Robert G. Wilson v, <a href="/A129377/b129377.txt">Table of n, a(n) for n = 1..50</a>.

%t f[n_] := Block[{c = 1, k = 4 n/3}, While[ !IntegerQ@k, c++; k = 4 Ceiling@k/3]; c]; t = Table[0, {1000}]; Do[ a = f@n; If[a < 101 && t[[a]] == 0, t[[a]] = n; Print[{a, n}]], {n, 0, 2800000}]

%Y Cf. A085068, A085071, A085328, A085330.

%K nonn

%O 1,1

%A _Robert G. Wilson v_, May 27 2007