A137607 - OEIS

%I #14 Mar 31 2024 12:24:11

%S 361,180,90,45,338,169,276,138,69,326,163,279,221,250,125,298,149,286,

%T 143,289,216,108,54,27,347,187,267,227,247,237,242,121,300,150,75,323,

%U 199,261,230,115,303,209,256,128,64,32,16,8,4,2,1,360,180,90,45,338,169,276,138,69,326,163,279,221,250,125,298,149,286,143,289,216,108,54,27,347,187,267,227,247,237,242,121,300,150,75,323,199,261,230,115,303,209,256,128,64,32,16,8,4,2,1,360

%N a(0)=361, a(n+1)=a(n)/2 if a(n) is even, else a(n+1)=a(0)-(a(n)+1)/2.

%C For n>=1, periodic with period 51. - _Vladeta Jovovic_, Apr 28 2008

%C The rule is the following: b(0)=361. If b(n-1) is divisible by 2 then b(n) = b(n-1)/2. If b(n-1) is not divisible by two then b(n) = b(0)-(b(n-1)+1)/2. It is periodic.

%H <a href="/index/Rec#order_51">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).

%t NestList[If[Mod[#,2]==0,#/2,361-(#+1)/2]&,361,110] (* _Harvey P. Dale_, Mar 31 2024 *)

%o (PARI) A137607(n) = if( !n,361, for( i=0,n%51, n=if( i, if( n%2, 360-n\2, n\2), 360)); n) \\ _M. F. Hasler_, Apr 28 2008

%Y Cf. A096259.

%K nonn,less

%O 0,1

%A _Yasutoshi Kohmoto_, Apr 23 2008

%E Clarified & extended by _Vladeta Jovovic_ and _M. F. Hasler_, Apr 28 2008

%E The initial term, 361, seems anomalous. This sequence violates the rule that entries in the OEIS should not depend on an arbitrary but large parameter. - _N. J. A. Sloane_, May 17 2008