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

1,1

Comments

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

Links

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

Example

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

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]

Crossrefs

Cf. A000032, A274348, A274349, A271354.

Sequence in context: A327297 A371464 A199981 * A316266 A179899 A085926

Adjacent sequences: A274344 A274345 A274346 * A274348 A274349 A274350

Keyword

nonn,easy

Author

Clark Kimberling, Jun 18 2016

Status

approved