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A151546 When computing A160256(n), it must be a multiple of a(n).

%I A151546 #11 Jun 11 2018 11:53:06
%S A151546 1,2,3,2,3,8,9,8,3,2,6,1,6,5,12,5,12,1,60,7,60,7,60,7,60,7,60,7,60,1,
%T A151546 420,11,420,11,420,11,420,11,420,11,420,11,420,11,420,22,378,55,126,
%U A151546 55,63,220,63,440,189,880,567,880,189,220,63,55,252,275,252,275,336,275,84,275,84
%N A151546 When computing A160256(n), it must be a multiple of a(n).
%C A151546 In other words, a(n) = numerator of b(n-2)/b(n-1), where b() = A160256().
%C A151546 Then b(n) = smallest multiple of a(n) not already present in A160256.
%H A151546 Alois P. Heinz, <a href="/A151546/b151546.txt">Table of n, a(n) for n = 3..10000</a>
%p A151546 bb:= proc(n) option remember; false end: b:= proc(n) option remember; local k, m; if n<3 then bb(n):= true; n else m:= denom(b(n-1) /b(n-2)); for k from m by m while bb(k) do od; bb(k):= true; k fi end: a:= n-> numer(b(n-2) /b(n-1)): seq(a(n), n=3..100); # _Alois P. Heinz_, May 17 2009
%t A151546 bb[n_] := bb[n] = False;
%t A151546 b[n_] := b[n] = Module[{k, m}, If[n < 3, bb[n] = True; n, m = Denominator[ b[n - 1] /b[n - 2]]; For[ k = m , bb[k], k += m]; bb[k] = True; k ]];
%t A151546 a[n_] := Numerator[b[n - 2] /b[n - 1]];
%t A151546 Table[a[n], {n, 3, 100}]
%K A151546 nonn,look
%O A151546 3,2
%A A151546 _N. J. A. Sloane_, May 16 2009