login
A324848
Number of prime indices of n (counted with multiplicity) that divide n.
17
0, 1, 0, 2, 0, 2, 0, 3, 0, 1, 0, 3, 0, 1, 1, 4, 0, 3, 0, 2, 0, 1, 0, 4, 0, 1, 0, 3, 0, 3, 0, 5, 0, 1, 0, 4, 0, 1, 0, 3, 0, 2, 0, 2, 1, 1, 0, 5, 0, 1, 0, 2, 0, 4, 1, 4, 0, 1, 0, 4, 0, 1, 0, 6, 0, 2, 0, 2, 0, 1, 0, 5, 0, 1, 2, 2, 0, 3, 0, 4, 0, 1, 0, 4, 0, 1, 0
OFFSET
1,4
COMMENTS
A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.
LINKS
EXAMPLE
The prime indices of 6776 are {1,1,1,4,5,5}, four of which {1,1,1,4} divide 6776, so a(6776) = 4.
MATHEMATICA
Table[Total[Cases[If[n==1, {}, FactorInteger[n]], {p_, k_}:>k/; Divisible[n, PrimePi[p]]]], {n, 100}]
CROSSREFS
The version for distinct prime indices is A324852.
Positions of zeros are A324846.
Positions of ones are A324856.
Sequence in context: A239246 A171700 A162660 * A090330 A332447 A132747
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 18 2019
STATUS
approved