A368114 - OEIS

%I #16 Feb 13 2026 13:14:54

%S 11,122,61,672,336,168,84,42,21,7,1,12,6,3,1,12,6,3,1,12,6,3,1,12,6,3,

%T 1,12,6,3,1,12,6,3,1,12,6,3,1,12,6,3,1,12,6,3,1,12,6,3,1,12,6,3,1,12,

%U 6,3,1,12,6,3,1,12,6,3,1,12,6,3,1,12,6,3,1,12,6,3,1

%N Trajectory of 11 under the '11x+1' map.

%C See A368085 for definition and cross references.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,1).

%F G.f.: (11 + 122*x + 61*x^2 + 672*x^3 + 325*x^4 + 46*x^5 + 23*x^6 - 630*x^7 - 315*x^8 - 161*x^9 - 83*x^10 - 30*x^11 - 15*x^12 - 4*x^13)/(1 - x^4). - _Stefano Spezia_, Jun 09 2024

%t Module[{lpf}, NestList[If[1 < (lpf = FactorInteger[#][[1, 1]]) < 11, #/lpf, #*11 + 1] &, 11, 100]] (* _Paolo Xausa_, Feb 13 2026 *)

%Y Cf. A368085.

%K nonn,easy

%O 0,1

%A _Paolo Xausa_, Dec 12 2023