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%I #9 Mar 31 2012 13:20:25
%S 1,3,6,15,12,45,24,36,48,405,60,315,192,144,120,945,180,1575,240,576,
%T 3072,295245,360,1296,12288,900,960,25515,720,14175,840,9216,196608,
%U 5184,1260,17325,786432,36864,1680,31185,2880,127575,15360,3600,99225
%N Smallest m such that the m-th Fibonacci number has exactly n divisors that are also Fibonacci numbers.
%C A076985(n) = A000045(a(n)); A076984(a(n)) = n.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/FibonacciNumber.html">Fibonacci Number</a>
%F Conjecture: a(2k+1) = 3*2^(Prime[k-1]-1) for k>3. It appears that a(2k+1) = 3*2^k for k = {1,2,3,4,6,10,12,16,18,...} = A068499[n] Numbers n such that n! reduced modulo (n+1) is not zero. - _Alexander Adamchuk_, Sep 15 2006
%e n=6: a(6) = 45, A076985(6) = A000045(45) = 1134903170,
%e A076984(45) = #{1,2,5,34,109441,1134903170} = #{fib(1),fib(2),fib(5),fib(9),fib(21),fib(45)} = 6.
%t t=Table[s=DivisorSigma[0, n]; If[OddQ[n], s, s-1], {n, 1000000}]; lst={}; n=1; While[pos=Flatten[Position[t, n, 1, 1]]; Length[pos]>0, AppendTo[lst, pos[[1]]]; n++ ]; lst (Noe)
%Y Cf. A068499.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Apr 20 2005
%E More terms from _T. D. Noe_, Jan 18 2006
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