A087226 LCM of terms in Collatz (3x+1) function initiated at n.

1, 2, 240, 4, 80, 240, 1361360, 8, 12252240, 80, 194480, 240, 1040, 1361360, 4095840, 16, 17680, 12252240, 107158480, 80, 1344, 194480, 1365280, 240, 535792400, 1040, 44841486948146266934850832405421294927083491752830032389039800908293040266400

Offset: 1

Author

Labos Elemer, Aug 28 2003

Keywords

• nonn

Examples

			n=9: list={9,28,14,7,22,11,34,17,52,26,13,40,20,10,5,16,8,4,2,1};
LCM = 2*2*2*2*3*3*5*7*11*13*17 = 12252240.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• Index entries for sequences related to 3x+1 (or Collatz) problem
• Index entries for sequences related to lcm's

Crossrefs

Cf. A006370.

Cf. A070165, A225784.

Programs

Haskell

a087226 = foldl1 lcm . a070165_row  -- Reinhard Zumkeller, May 16 2013

Mathematica

c[x_] := (1-Mod[x, 2])*(x/2)+Mod[x, 2]*(3*x+1); c[1]=1; fpl[x_] := Delete[FixedPointList[c, x], -1] Table[Apply[LCM, fpl[w]], {w, 1, 32}]
Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; Table[LCM @@ Collatz[n], {n, 27}] (* T. D. Noe, May 15 2013 *)