A063042 Collatz-2 (A063041) trajectory starting at 3.

3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9, 3, 7, 36, 18, 9

Offset: 0

Author

Reinhard Zumkeller, Jul 07 2001

Keywords

• nonn
• easy

Comments

a(0) = a(5) = 3

Crossrefs

A063041.

Programs

Mathematica

NestList[If[PrimeQ[#],#*Prime[PrimePi[#]-1]+1,#/Min@@First/@FactorInteger[#]]&,3,104] (* Jayanta Basu, May 27 2013 *)

Formula

a(0) = 3 and a(n) = A063041(a(n-1)) for n > 0