A129377 First occurrence of n in A085068.

3, 2, 1, 17, 19, 14, 10, 7, 5, 500, 404, 311, 233, 215, 161, 2363, 1772, 3097, 11474, 8605, 8234, 6175, 4631, 3473, 34196, 30779, 23084, 38752, 422549, 335165, 1500443, 1125332, 2039653, 2762863, 2072147, 1554110, 1165582, 874186, 655639, 491729

Offset: 1

Author

Robert G. Wilson v, May 27 2007

Keywords

• nonn

Comments

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.

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

Links

• Robert G. Wilson v, Table of n, a(n) for n = 1..50.

Crossrefs

Cf. A085068, A085071, A085328, A085330.

Programs

Mathematica

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}]