A098893 Sum of number of prime-factors of all prefixes in decimal representation of n.

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

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: A326191 A326189 A324190 * A302037 A069248 A329378

Adjacent sequences: A098890 A098891 A098892 * A098894 A098895 A098896

Keyword

nonn,base

Author

Reinhard Zumkeller, Nov 04 2004

Status

approved