|
%I #22 Jan 28 2020 22:30:39
%S 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,
%T 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,
%U 19,10,9,8,9,6,16,6,26,10,9,8,11,6,42,14,7,20,5,4,3
%N Smallest k such that tau(Fibonacci(k))= tau(Fibonacci(n+k)).
%C tau(n) is the number of divisors of n (A000005).
%H Chai Wah Wu, <a href="/A174280/b174280.txt">Table of n, a(n) for n = 1..1284</a>
%H Eric W. Weisstein, <a href="http://mathworld.wolfram.com/DivisorFunction.html">MathWorld: Divisor Function</a>
%e a(2)= 3 because tau(Fibonacci(3))= tau(2)= 2, tau(Fibonacci(3+2)=tau(5)= 2.
%p with(numtheory) ;
%p with(combinat) ;
%p A174280 := proc(n)
%p for k from 1 do
%p if tau(fibonacci(k)) = tau(fibonacci(n+k)) then
%p return k;
%p end if;
%p end do:
%p end proc:
%p seq(A174280(n),n=1..80) ; # _R. J. Mathar_, Jul 06 2012
%t Table[k = 1; While[DivisorSigma[0, Fibonacci[k]] != DivisorSigma[0, Fibonacci[k + n]], k++]; k, {n, 100}] (* _T. D. Noe_, Mar 18 2013 *)
%Y Cf. A063375.
%K nonn
%O 1,2
%A _Michel Lagneau_, Mar 15 2010
|
