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

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A098893 Sum of number of prime-factors of all prefixes in decimal representation of n. 0
0, 1, 1, 2, 1, 2, 1, 3, 2, 2, 1, 3, 1, 2, 2, 4, 1, 3, 1, 4, 3, 3, 2, 5, 3, 3, 4, 4, 2, 4, 2, 6, 3, 3, 3, 5, 2, 3, 3, 6, 3, 5, 3, 5, 5, 4, 3, 7, 4, 4, 3, 4, 2, 5, 3, 5, 3, 3, 2, 6, 3, 4, 5, 8, 4, 5, 3, 5, 4, 4, 2, 6, 2, 3, 4, 4, 3, 4, 2, 8, 7, 5, 4, 7, 5, 5, 5, 7, 4, 6, 4, 5, 4, 4, 4, 8, 3, 5, 5, 6, 3, 5, 3, 6, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

a(n) = if n<10 then Omega(n) else Omega(n) + a(floor(n/10)), where Omega=A001222.

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

a(256)=Omega(256)+a(25)=8+Omega(25)+a(2)=8+2+Omega(2)=10+1=11.

CROSSREFS

Sequence in context: A179953 A086436 A001222 * A069248 A008481 A127669

Adjacent sequences:  A098890 A098891 A098892 * A098894 A098895 A098896

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Nov 04 2004

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 November 23 00:10 EST 2014. Contains 249835 sequences.