A333578 Numbers k such that a division occurs in A330139(k).

5, 12, 21, 172, 15277, 703981, 2060911, 6663113

Offset

1,1

Comments

Is this sequence infinite?

Links

Table of n, a(n) for n=1..8.

Example

5 is in this sequence because a division occurs in A330139(5).

Mathematica

seq = {}; n1 = n2 = 1; Do[n3 = n1 + n2; If[Divisible[n3, n], n3/=n; AppendTo[seq, n]]; n1 = n2; n2 = n3, {n, 3, 2*10^4}]; seq (* Amiram Eldar, Mar 28 2020 *)

Prog

(C#)
static void Main(string[] args)
{
   BigInteger[] n = new BigInteger[3];
   BigInteger count = 3;
   n[0] = 1;
   n[1] = 1;
   short a = 0;
   while (a == 0)
   {
      n[2] = n[1] + n[0];
      if (n[2] % count == 0)
      {
         n[2] = n[2] / count;
         Console.WriteLine(count);
      }
      n[0] = n[1];
      n[1] = n[2];
      count++;
   }
}
(PARI) lista(nn) = {my(x = 1, y = 1, z); for (n=3, nn, z = x + y; if ((z % n) == 0, z = z/n; print1(n, ", ")); x = y; y = z; ); } \\ Michel Marcus, Mar 27 2020

Crossrefs

Cf. A330139.

Sequence in context: A345714 A242338 A217649 * A131976 A074376 A293502

Adjacent sequences: A333575 A333576 A333577 * A333579 A333580 A333581

Keyword

nonn,more

Author

Eder Vanzei, Mar 27 2020

Status

approved