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A050122 a(n) = n-th number of the form F(i)*L(j), i<=j, when these products of Fibonacci and Lucas numbers are ordered, without duplicates. 2

%I

%S 0,1,3,4,7,8,11,14,18,21,22,29,33,36,47,54,55,58,76,87,90,94,123,141,

%T 144,145,152,199,228,232,235,246,322,369,376,377,380,398,521,597,608,

%U 611,615,644,843,966,984,987,988,995,1042,1364

%N a(n) = n-th number of the form F(i)*L(j), i<=j, when these products of Fibonacci and Lucas numbers are ordered, without duplicates.

%H R. J. Mathar, <a href="/A050122/b050122.txt">Table of n, a(n) for n = 1..171</a>

%p isA050122 := proc(n)

%p local i,j,f,l ;

%p if n =0 then

%p true;

%p else

%p for i from 1 do

%p f := A000045(i) ;

%p if f > n then

%p return false;

%p else

%p for j from i do

%p l := A000032(j) ;

%p if f*l = n then

%p return true;

%p elif f*l > n and j> 2 then

%p break;

%p end if;

%p end do:

%p end if;

%p end do:

%p end if;

%p end proc:

%p A050122 := proc(n)

%p option remember;

%p local a;

%p if n = 1 then

%p 0;

%p else

%p for a from procname(n-1)+1 do

%p if isA050122(a) then

%p return a;

%p end if;

%p end do:

%p end if;

%p end proc:

%p seq(A050122(n),n=1..80) ; # _R. J. Mathar_, Jan 04 2017

%Y Cf. A000032, A000045.

%K nonn

%O 1,3

%A _Clark Kimberling_

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Last modified May 6 03:23 EDT 2021. Contains 343580 sequences. (Running on oeis4.)