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A008873
3x+1 sequence starting at 97.
4
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.
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
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), Apr 27 2001
STATUS
approved