login
3x+1 sequence starting at 95.
5

%I #27 Sep 08 2022 08:44:36

%S 95,286,143,430,215,646,323,970,485,1456,728,364,182,91,274,137,412,

%T 206,103,310,155,466,233,700,350,175,526,263,790,395,1186,593,1780,

%U 890,445,1336,668,334,167,502,251,754,377,1132,566,283,850,425,1276,638,319,958,479,1438,719,2158,1079,3238

%N 3x+1 sequence starting at 95.

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

%H T. D. Noe, <a href="/A008875/b008875.txt">Table of n, a(n) for n=0..105</a>

%H <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a>

%F a(n) = A008874(n + 2).

%p f := proc(n) option remember; if n = 0 then 95; elif f(n-1) mod 2 = 0 then f(n-1)/2 else 3*f(n-1)+1; fi; end;

%t NestList[If[EvenQ[#],#/2,3#+1]&,95,60] (* _Harvey P. Dale_, Dec 02 2012 *)

%o (Haskell)

%o a008875 n = a008875_list !! n

%o a008875_list = drop 2 a008874_list

%o -- _Reinhard Zumkeller_, Aug 30 2012

%o (Magma) [n eq 1 select 95 else IsOdd(Self(n-1)) select 3*Self(n-1)+1 else Self(n-1) div 2: n in [1..70]]; // _Vincenzo Librandi_, Jul 29 2014

%Y Cf. A006370, A008874.

%Y Row 95 of A347270.

%K nonn

%O 0,1

%A _N. J. A. Sloane_.

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