login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A158584 The integer part of the geometric mean of the prime factors of n with multiplicity. 0
2, 3, 1, 5, 2, 7, 1, 3, 3, 11, 2, 13, 3, 3, 1, 17, 2, 19, 2, 4, 4, 23, 2, 4, 5, 3, 3, 29, 3, 31, 1, 5, 5, 5, 2, 37, 6, 6, 2, 41, 3, 43, 3, 3, 6, 47, 2, 7, 3, 7, 3, 53, 2, 7, 2, 7, 7, 59, 2, 61, 7, 3, 1, 8, 4, 67, 4, 8, 4, 71, 2, 73, 8, 4, 4, 8, 4, 79, 2, 3, 9, 83, 3, 9, 9, 9, 3, 89, 3, 9, 4, 9, 9, 9, 2, 97 (list; graph; refs; listen; history; internal format)
OFFSET

2,1

COMMENTS

We do not begin with the unit 1 because it has no prime factors. Conjecture:

The sequence contains the set of prime numbers more than once.

FORMULA

The geometric mean is the n-th root of the product of n numbers.

Gm = (a(1)*a(2)*...*a(n))^(1/n).

EXAMPLE

12=2*2*3 has 3 factors; 12^(1/3) = 2.289428... so 2 is in the 11th position in

the sequence.

PROG

(PARI) g(n) = for(x=2, n, print1(floor(x^(1/bigomega(x)))", "))

CROSSREFS

Sequence in context: A055023 A126773 A134194 * A086112 A138798 A134734

Adjacent sequences:  A158581 A158582 A158583 * A158585 A158586 A158587

KEYWORD

nonn

AUTHOR

Cino Hilliard (hillcino368(AT)hotmail.com), Mar 21 2009

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 14 19:37 EST 2012. Contains 205663 sequences.