A087973 Maximal term in Collatz-iteration started at 3^n.

16, 52, 9232, 244, 9232, 2464, 10528, 19684, 88576, 2270104, 1008916, 1594324, 7174456, 65451076, 64570084, 129140164, 1570824736, 1961316232, 8825923024, 10460353204, 47071589416, 105911076184, 423644304724, 66034034786644

Offset: 1

Author

Labos Elemer, Sep 24 2003

Keywords

• nonn

Examples

			Compare to A087972, when iv=1+3^n.
		

Crossrefs

Cf. A025586, A087701, A087972.

Programs

Mathematica

Table[Max[NestList[If[EvenQ[#],#/2,3#+1]&,3^n,100]],{n,25}] (* Harvey P. Dale, Dec 08 2011 *)

Formula

a(n)=A025586[3^n]=A025586[1+3^(n+1)]=A087972[n+1]