cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A097034 Initial values for iteration of the function f(x) = A063919(x) such that the iteration ends in a 14-cycle, i.e., in A097030.

Original entry on oeis.org

1506, 1518, 1806, 1902, 1914, 1938, 1950, 2226, 2382, 2394, 2406, 2418, 2478, 2826, 2910, 2946, 2958, 3234, 3282, 3294, 3330, 3510, 3522, 3534, 3546, 3582, 3642, 3654, 3774, 3906, 3954, 3966, 3978, 4146, 4158, 4194, 4434, 4446, 4854, 4866, 4878, 5262
Offset: 1

Views

Author

Labos Elemer, Aug 30 2004

Keywords

Examples

			n=1506 is here because its iteration list = {1506, 1518, 1938, 2382, 2394, 2406, [2418, ...., 3582, 2418}. After a transient of length 6, the iteration ends in a cycle of length 14.
		

Crossrefs

Programs

  • Mathematica
    a063919[1] = 1; (* function a[] in A063919 by Jean-François Alcover *)
    a063919[n_] :=
     Total[Select[Divisors[n], GCD[#, n/#] == 1 &]] - n /; n > 1
    a097034Q[k_] :=
     Module[{iter = NestWhileList[a063919, k, UnsameQ, All]},
      Apply[Subtract, Reverse[Flatten[Position[iter, Last[iter]], 1]]] ==
       14]
    a097034[n_] := Select[Range[n], a097034Q]
    a097034[5262] (* Hartmut F. W. Hoft, Jan 25 2024 *)