A075739 - OEIS

%I #10 Aug 20 2019 09:14:17

%S 144,2584,46368,75025,14930352,4807526976,12586269025,86267571272,

%T 225851433717,1548008755920,498454011879264,2111485077978050,

%U 160500643816367088,2880067194370816120,51680708854858323072,354224848179261915075,16641027750620563662096

%N Nonsquarefree Fibonacci numbers whose indices are also not squarefree.

%e Fib(18)=2584 is there because neither 18 nor 2584 is squarefree.

%p with(combinat, fibonacci): fib_supM_ndsk := proc(n); if (numtheory[issqrfree](n)='false') then if (numtheory[issqrfree](fibonacci(n))='false') then RETURN(fibonacci(n)); fi; fi; end: seq(fib_supM_ndsk(i), i=1..200);

%t Select[Table[{n,Fibonacci[n]},{n,300}],NoneTrue[#,SquareFreeQ]&][[All,2]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Aug 20 2019 *)

%Y Cf. A000045, A013929, A061899, A075738.

%K easy,nonn

%O 1,1

%A _Jani Melik_, Oct 07 2002

%E Edited by _Don Reble_, Nov 05 2005

%E More terms from _Harvey P. Dale_, Aug 20 2019