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Products of 2 distinct Fibonacci numbers and products of two distinct Lucas numbers (without 2), arranged in increasing order.
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%I #11 Oct 30 2017 03:41:38

%S 0,2,3,4,5,6,7,8,10,11,12,13,15,16,18,21,24,26,28,29,33,34,39,40,42,

%T 44,47,54,55,63,65,68,72,76,77,87,89,102,104,105,110,116,123,126,141,

%U 144,165,168,170,178,188,198,199,203,228,233,267,272,273,275,288

%N Products of 2 distinct Fibonacci numbers and products of two distinct Lucas numbers (without 2), arranged in increasing order.

%C Are 3 and 21 the only numbers that are a product of two distinct Fibonacci numbers and also a product of two distinct Lucas numbers?

%H G. C. Greubel, <a href="/A274374/b274374.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]; t = Take[Sort[Flatten[Table[g[u] g[v], {u, 1, z}, {v, 1, u - 1}]]], z]

%t Union[s, t]

%Y Cf. A049862, A274347, A274375.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Jun 19 2016