A060319 Smallest Fibonacci number with n distinct prime factors.

1, 2, 21, 610, 6765, 832040, 102334155, 190392490709135, 1548008755920, 23416728348467685, 2880067194370816120, 81055900096023504197206408605, 2706074082469569338358691163510069157, 5358359254990966640871840, 57602132235424755886206198685365216, 18547707689471986212190138521399707760

Offset

0,2

Links

Amiram Eldar, Table of n, a(n) for n = 0..40

Ron Knott, Fibonacci numbers with tables of F(0)-F(500)

Example

a(5) = F(30) = 832040 = 2^3 * 5 * 11 * 41 * 61.

Mathematica

f[n_]:=Length@FactorInteger[Fibonacci[n]]; lst={}; Do[Do[If[f[n]==q, Print[Fibonacci[n]]; AppendTo[lst, Fibonacci[n]]; Break[]], {n, 280}], {q, 18}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 23 2009 *)
First /@ SortBy[#, Last] &@ Map[#[[1]] &, Values@ GroupBy[#, Last]] &@ Table[{#, PrimeNu@ #} &@ Fibonacci@ n, {n, 2, 200}] (* Michael De Vlieger, Feb 18 2017, Version 10 *)

Crossrefs

Cf. A001605, A005478, A060320.

Row n=1 of A303218.

Sequence in context: A320653 A302686 A078602 * A095224 A034984 A024233

Adjacent sequences: A060316 A060317 A060318 * A060320 A060321 A060322

Keyword

nonn

Author

Labos Elemer, Mar 28 2001

Status

approved