A350035 Number of steps to reach 1 under repeated applications of the A350034 map, or -1 if 1 is never reached.
0, 1, 1, 2, 11, 1, 3, 3, 2, 12, 7, 2, 9, 4, 12, 4, 6, 2, 6, 13, 4, 8, 16, 3, 6, 10, 3, 5, 13, 12, 12, 5, 8, 7, 12, 2, 14, 7, 10, 14, 9, 4, 4, 9, 13, 17, 21, 4, 11, 7, 7, 11, 19, 3, 19, 6, 7, 14, 18, 13, 9, 13, 5, 6, 13, 8, 8, 8, 17, 13, 20, 3, 11, 15, 7, 8, 15, 10, 10, 15, 4, 10, 15, 5, 22, 5
Offset: 1
Keywords
Examples
5 -> 26 -> 13 -> 66 -> 11 -> 56 -> 28 -> 14 -> 7 -> 36 -> 6 -> 1. Thus a(5) = 11.
Links
- Winston de Greef, Table of n, a(n) for n = 1..10000
Programs
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Maple
a:= proc(n) option remember; `if`(n=1, 0, 1+ a((g-> `if`(g>1, n/g, 5*n+1))(igcd(n, 6)))) end: seq(a(n), n=1..100); # Alois P. Heinz, Jan 19 2022 -
Mathematica
f[n_]:=If[GCD[n,6]>1,n/GCD[n,6],5*n+1];Table[f[n],{n,0,100}]; S[n_]:=S[n]=Which[n==1,0,f[n]==1,1,True,1+S[f[n]]]; Table[S[n],{n,1,86}] -
PARI
A350034(n) = my(g = gcd(n, 6)); if (g>1, n/g, 5*n+1); a(n)=my(r=0); while(n != 1, n = A350034(n); r+=1); r \\ Winston de Greef, Oct 02 2023