A008873 3x+1 sequence starting at 97.

97, 292, 146, 73, 220, 110, 55, 166, 83, 250, 125, 376, 188, 94, 47, 142, 71, 214, 107, 322, 161, 484, 242, 121, 364, 182, 91, 274, 137, 412, 206, 103, 310, 155, 466, 233, 700, 350, 175, 526, 263, 790, 395, 1186, 593, 1780, 890, 445, 1336, 668, 334, 167, 502, 251, 754, 377, 1132, 566, 283, 850, 425

Offset

0,1

References

R. K. Guy, Unsolved Problems in Number Theory, E16.

Links

T. D. Noe, Table of n, a(n) for n=0..118

Index entries for sequences related to 3x+1 (or Collatz) problem

Maple

f := proc(n) option remember; if n = 0 then 97; elif f(n-1) mod 2 = 0 then f(n-1)/2 else 3*f(n-1)+1; fi; end;

Mathematica

NestList[If[EvenQ[#], #/2, 3# + 1]&, 97, 100] (* Vincenzo Librandi, Jul 29 2014 *)

Prog

(Haskell)
a008873 n = a008873_list !! n
a008873_list = 97 : iterate a006370 97
-- Reinhard Zumkeller, Aug 30 2012
(Magma) [n eq 1 select 97 else IsOdd(Self(n-1)) select 3*Self(n-1)+1 else Self(n-1) div 2: n in [1..80]]; // Vincenzo Librandi, Jul 29 2014

Crossrefs

Cf. A006370.

Row 97 of A347270.

Sequence in context: A141986 A123033 A142008 * A142455 A159507 A141899

Adjacent sequences: A008870 A008871 A008872 * A008874 A008875 A008876

Keyword

nonn

Author

N. J. A. Sloane.

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Apr 27 2001

Status

approved