A335773 Numbers k such that A334943(k) = 1.

1, 4, 37, 196, 1315, 1941, 2428, 2451, 3223, 5613, 5681, 6758, 9141, 12768, 15507, 16206, 20076, 21373, 28827, 30252, 33442, 37466, 40332, 47532, 59355, 81769, 92446, 94669, 99424, 109089, 114423, 123253, 129186, 149073, 191288, 200654, 202489, 212787, 229372, 234825, 237832, 284586, 300355

Offset

1,2

Comments

Sequence consists of 1 and numbers k such that A334943(k-1) | k.

Links

Robert Israel, Table of n, a(n) for n = 1..1000

Maple

count:= 1: v:= 1: R:= 1:
for n from 2 while count < 100 do
   g:= igcd(v, n);
   if g > 1 then v:= v/g else v:= 3*v+n+1 fi;
   if v = 1 then count:= count+1; R:= R, n; fi
od:
R;

Mathematica

Position[Nest[Append[#1, If[#3 > 1, #1[[-1]]/#3, 3 #1[[-1]] + #2 + 1]] & @@ {#1, #2, GCD[#1[[-1]], #2]} & @@ {#, Length@ # + 1} &, {1}, 10^5], 1][[All, 1]] (* Michael De Vlieger, Jun 22 2020 *)

Crossrefs

Cf. A334943.

Sequence in context: A273684 A063418 A095819 * A201865 A025542 A162649

Adjacent sequences: A335770 A335771 A335772 * A335774 A335775 A335776

Keyword

nonn

Author

Robert Israel, Jun 22 2020

Status

approved