[Guest]

1,2,3,2,5,1,7,2,3,1,11,3,13,1,5,2,17,1,?,?,?,?,?,?

[Guest]

1,2,3,2,5,1,7,2,3,1,11,3,13,1,5,2,17,1,?,?,?,?,?,?

the nth term of the sequence is the smallest factor of n which can be multiplied by some subgroup of terms 1 through n-1 of the sequence to produce n?

So the next 6 terms would be:

19,1,1,1,23,1

EDIT: Nevermind, this doesn't work for the 12th or 15th terms.

Edited April 19, 2009 by hookemhorns

[Guest]

1,2,3,2,5,1,7,2,3,1,11,3,13,1,5,2,17,1,?,?,?,?,?,?

is the answer 3, 19, 2, 7, 2, 23?

[Guest]

19,5,1,11,23,1

19,1,7,11,23,1

1,2,3,2,5,1,7,2,3,1,11,3,13,1,5,2,17,1,?,?,?,?,?,?

Edited April 19, 2009 by varnejm

[Guest]

1,2,3,2,5,1,7,2,3,1,11,3,13,1,5,2,17,1,?,?,?,?,?,?

19 5 7 11 23

n= highest factor that has already been in the sequence....(i hope)

[Guest]

I can see a pattern of course... the primes are easily recognizable

I don't see the real sequence.

a(n) = 1 , except when:

- a is a prime, or

- a is a prime power of a(n)

If this is even valid as a number sequence solution (given the exceptions) it fits most of the sequence. However, it does not work for n=12, or n=15.

[Guest]

I can see a pattern of course... the primes are easily recognizable

I don't see the real sequence.

a(n) = 1 , except when:

- a is a prime, or

- a is a prime power of a(n)

If this is even valid as a number sequence solution (given the exceptions) it fits most of the sequence. However, it does not work for n=12, or n=15.

a(n) = 1 , except when:

- n is a prime, or

- n is a prime power of a(n)

Still I did not get any closer to a solution. Any ideas?

[Guest]

19,1,7,11,23,1

You're right!

What I want to know is HTH you got that.

Edited April 19, 2009 by Romulus064

[Pickett]

You're right!

What I want to know is HTH you got that.

I can get the same answer as varnejm, using this formula:

f(n) = 1 if n has 2 distinct prime factors, one of which is a 2 or n = 1

f(n) = 2 if n is a power of 2

f(n) = n if n is prime

f(n) = largest prime factor of n for all other cases

However, the only number that doesn't seem to work with that is n=12..because the factorization of 12 is 2, 2, 3...which has 2 distinct prime factors, one of which is a 2...so, I would think that it would be "1"...but the sequence says it is "3"...so I think I'm missing something...but that's what I have so far.