A075742 Fibonacci numbers, which are the product of an odd number of distinct primes for numbers with the same property (mu(n)=mu(fibonacci(n))=-1).

2, 5, 13, 89, 233, 1597, 28657, 514229, 24157817, 433494437, 2971215073, 44945570212853, 190392490709135, 99194853094755497, 83621143489848422977, 1500520536206896083277, 3928413764606871165730

Offset

1,1

Links

Table of n, a(n) for n=1..17.

Example

11 is a prime and fibonacci(11)=89 is a prime, 13 is a prime and fibonacci(13)=233 is a prime, but fibonacci(16)=987=3*7*47 and 16 is not squarefree and 30=2*3*5 is the product of an odd number of distinct primes but fibonacci(30)=832040=2^3*5*11*31*61 is not squarefree, ...

Maple

with(combinat, fibonacci): m2_supM_fib := proc(n); if (numtheory[mobius](n)=-1) then if (numtheory[mobius](fibonacci(n))=-1) then RETURN(fibonacci(n)); fi; fi; end:

Crossrefs

Cf. A000045, A030059, A074691.

Sequence in context: A325627 A075736 A030426 * A075737 A100843 A082101

Adjacent sequences: A075739 A075740 A075741 * A075743 A075744 A075745

Keyword

easy,nonn

Author

Jani Melik, Oct 07 2002

Status

approved