A057685 Trajectory of 19 under the `19x+1' map.

19, 362, 181, 3440, 1720, 860, 430, 215, 43, 818, 409, 7772, 3886, 1943, 36918, 18459, 6153, 2051, 293, 5568, 2784, 1392, 696, 348, 174, 87, 29, 552, 276, 138, 69, 23, 438, 219, 73, 1388, 694, 347, 6594, 3297, 1099, 157, 2984, 1492, 746, 373, 7088, 3544, 1772, 886, 443

Offset

0,1

Comments

See A057684 for definition.

Links

T. D. Noe, Table of n, a(n) for n=0..72

Index entries for linear recurrences with constant coefficients, signature (0,0,0,1).

Mathematica

Module[{lpf}, NestList[If[1 < (lpf = FactorInteger[#][[1, 1]]) < 19, #/lpf, #*19 + 1] &, 19, 50]] (* Paolo Xausa, Feb 12 2026 *)

Crossrefs

Cf. A057446, A057216, A057522, A057534, A057614.

See also A033478, A057688, A057684, A057686, A057687, A057689, A057690, A057691, A368085, A368114, A368115, A368159.

Sequence in context: A045609 A128360 A001029 * A243399 A041686 A263371

Adjacent sequences: A057682 A057683 A057684 * A057686 A057687 A057688

Keyword

nonn,easy

Author

N. J. A. Sloane, Oct 20 2000

Status

approved