login
Products of 2 distinct Fibonacci numbers and products of two distinct Lucas numbers (including 2), arranged in increasing order.
2

%I #9 Oct 31 2017 12:39:39

%S 0,2,3,4,5,6,7,8,10,11,12,13,14,15,16,18,21,22,24,26,28,29,33,34,36,

%T 39,40,42,44,47,54,55,58,63,65,68,72,76,77,87,89,94,102,104,105,110,

%U 116,123,126,141,144,152,165,168,170,178,188,198,199,203,228,233

%N Products of 2 distinct Fibonacci numbers and products of two distinct Lucas numbers (including 2), arranged in increasing order.

%C Are 2,3,6,8,21 the only numbers that are a product of two distinct Fibonacci numbers and also a product of two distinct Lucas numbers (including 2)?

%H G. C. Greubel, <a href="/A274375/b274375.txt">Table of n, a(n) for n = 1..5000</a>

%t z = 400; f[n_] := Fibonacci[n];

%t s = Join[{0}, Take[Sort[Flatten[Table[f[m] f[n], {n, 2, z}, {m, 2, n - 1}]]], z]]

%t g[n_] := LucasL[n - 1]; t = Take[Sort[Flatten[Table[g[u] g[v], {u, 1, z}, {v, 1, u - 1}]]], z]

%t Union[s, t]

%Y Cf. A049862, A274349, A274374.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Jun 19 2016