login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Positions in A274429 of products of distinct Fibonacci numbers > 1.
3

%I #4 Jun 22 2016 23:16:13

%S 3,5,8,9,12,13,17,18,19,23,24,25,30,31,32,33,38,39,40,41,47,48,49,50,

%T 51,57,58,59,60,61,68,69,70,71,72,73,80,81,82,83,84,85,93,94,95,96,97,

%U 98,99,107,108,109,110,111,112,113,122,123,124,125,126,127

%N Positions in A274429 of products of distinct Fibonacci numbers > 1.

%C Complement of A274431.

%t z = 200; f[n_] := Fibonacci[n];

%t u = Take[Sort[Flatten[Table[f[m] f[n], {n, 3, z}, {m, 3, n - 1}]]], 100]

%t g[n_] := LucasL[n];

%t v = Take[Sort[Flatten[Table[g[u] g[v], {u, 1, z}, {v, 1, u - 1}]]], z]

%t Intersection[u, v]

%t w = Union[u, v] (* A274429 *)

%t Select[Range[300], MemberQ[u, w[[#]]] &] (* A274430 *)

%t Select[Range[300], MemberQ[v, w[[#]]] &] (* A274431 *)

%Y Cf. A274429, A274431.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, Jun 22 2016