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A174280
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Smallest k such that tau(Fibonacci(k))= tau(Fibonacci(n+k)).
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1
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1, 3, 4, 3, 9, 5, 4, 3, 4, 3, 8, 5, 4, 3, 19, 6, 9, 5, 4, 3, 10, 7, 8, 5, 4, 3, 14, 6, 33, 13, 10, 9, 8, 13, 6, 7, 18, 5, 4, 3, 21, 5, 4, 3, 8, 16, 6, 31, 10, 9, 8, 9, 6, 19, 6, 18, 14, 27, 14, 19, 10, 9, 8, 9, 6, 16, 6, 26, 10, 9, 8, 11, 6, 42, 14, 7, 20, 5, 4, 3
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OFFSET
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1,2
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COMMENTS
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tau(n) is the number of divisors of n (A000005).
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LINKS
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EXAMPLE
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a(2)= 3 because tau(Fibonacci(3))= tau(2)= 2, tau(Fibonacci(3+2)=tau(5)= 2.
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MAPLE
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with(numtheory) ;
with(combinat) ;
for k from 1 do
if tau(fibonacci(k)) = tau(fibonacci(n+k)) then
return k;
end if;
end do:
end proc:
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MATHEMATICA
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Table[k = 1; While[DivisorSigma[0, Fibonacci[k]] != DivisorSigma[0, Fibonacci[k + n]], k++]; k, {n, 100}] (* T. D. Noe, Mar 18 2013 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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