A346593 Numbers k such that A006577(k^3) sets a new record.

2, 3, 6, 7, 14, 15, 25, 41, 45, 71, 79, 153, 233, 235, 470, 503, 707, 741, 1482, 2964, 3039, 3581, 7162, 14324, 27337, 54674, 61683, 123366, 168159, 254251, 302839, 605678, 622699, 947173, 1618687, 3237374, 6474748, 10995401, 13042083, 21767875, 43535750, 48584565

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Index entries for sequences related to 3x+1 (or Collatz) problem

Mathematica

s[n_]:=s[n]=(i=0; r=n; While[r!=1, i++; If[EvenQ@r, r=r/2, r=r*3+1]]; i);
lst={}; max=1; Do[t=s[k^3]; If[t>max, AppendTo[lst, k]; max=t], {k, 10^4}]; lst (* Giorgos Kalogeropoulos, Jul 28 2021 *)

Prog

(PARI) a6577(n0)={my(n=n0, k=0); while(n>1, k++; n=if(n%2, 3*n+1, n/2)); k};
a346593(limit)={msteps=0; for(k=1, limit, my(m=a6577(k^3)); if(m>msteps, print1(k, ", "); msteps=m))};
a346593(1000000)

Crossrefs

Cf. A006577, A006877, A244638, A346591, A346592.

Sequence in context: A092482 A335099 A147303 * A066880 A075427 A075426

Adjacent sequences: A346590 A346591 A346592 * A346594 A346595 A346596

Keyword

nonn

Author

Hugo Pfoertner, Jul 28 2021

Status

approved