A274347 Products of two distinct Lucas numbers (3,4,7,11,18,...).

12, 21, 28, 33, 44, 54, 72, 77, 87, 116, 126, 141, 188, 198, 203, 228, 304, 319, 329, 369, 492, 517, 522, 532, 597, 796, 836, 846, 861, 966, 1288, 1353, 1363, 1368, 1393, 1563, 2084, 2189, 2204, 2214, 2254, 2529, 3372, 3542, 3567, 3572, 3582, 3647, 4092

Offset: 1

Author

Clark Kimberling, Jun 18 2016

Keywords

• nonn
• easy

Comments

L(i)*L(j) = L(i+j) + (-1)^i*L(j-i). - Robert Israel, Sep 02 2019

Examples

			12 = 3*4, 21 = 3*7.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000032, A274348, A274349, A271354.

Programs

Maple

L:= gfun:-rectoproc({f(n+1)=f(n)+f(n-1),f(0)=2,f(1)=1},f(n),remember):
Q:= proc(n) local j; op(sort([seq(L(n)+(-1)^j*L(n-2*j),j=2..(n-1)/2)])) end proc:
map(Q, [$5..20]); # Robert Israel, Sep 02 2019

Mathematica

z = 100; f[n_] := LucasL[n];
Take[Sort[Flatten[Table[f[u] f[v], {u, 2, z}, {v, 2, u - 1}]]], z]