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

 

Logo

Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A069352 Total number of prime factors of 3-smooth numbers. 10
0, 1, 1, 2, 2, 3, 2, 3, 4, 3, 4, 3, 5, 4, 5, 4, 6, 5, 4, 6, 5, 7, 6, 5, 7, 6, 5, 8, 7, 6, 8, 7, 6, 9, 8, 7, 6, 9, 8, 7, 10, 9, 8, 7, 10, 9, 8, 11, 7, 10, 9, 8, 11, 10, 9, 12, 8, 11, 10, 9, 12, 8, 11, 10, 13, 9, 12, 11, 10, 13, 9, 12, 11, 14, 10, 13, 9, 12, 11, 14, 10, 13, 12, 15, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

a(n) = A001222(A003586(n));

a(n) = A022328(n) + A022329(n);

A086414(n) <= A086415(n) <= a(n).

LINKS

Zak Seidov, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = i+j for 3-smooth numbers n = 2^i*3^j (A003586).

a(n) = A001222(A033845(n))-2. - Enrique PĂ©rez Herrero, Jan 04 2012

CROSSREFS

Sequence in context: A115727 A115726 A086413 * A073453 A123229 A127095

Adjacent sequences:  A069349 A069350 A069351 * A069353 A069354 A069355

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Mar 18 2002

EXTENSIONS

Edited by N. J. A. Sloane, Oct 27 2008 at the suggestion of R. J. Mathar.

STATUS

approved

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

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

Last modified September 3 03:50 EDT 2014. Contains 246369 sequences.