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A326154 Denominator of the product of prime indices of n divided by the sum of prime indices of n, n > 1. 11
1, 1, 2, 1, 3, 1, 3, 1, 4, 1, 2, 1, 5, 5, 4, 1, 5, 1, 5, 3, 6, 1, 5, 2, 7, 3, 3, 1, 1, 1, 5, 7, 8, 7, 3, 1, 9, 2, 2, 1, 7, 1, 7, 7, 10, 1, 3, 1, 7, 9, 4, 1, 7, 8, 7, 5, 11, 1, 7, 1, 12, 1, 6, 1, 4, 1, 9, 11, 2, 1, 7, 1, 13, 4, 5, 9, 3, 1, 7, 1, 14, 1, 1, 10 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,3

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

Table of n, a(n) for n=2..85.

EXAMPLE

The sequence A326153/A326154 begins: 1, 1, 1/2, 1, 2/3, 1, 1/3, 1, 3/4, 1, 1/2, 1, 4/5, 6/5, 1/4, 1, 4/5, 1, 3/5, 4/3, 5/6, 1, 2/5, 3/2, 6/7, 4/3.

MATHEMATICA

primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];

Table[Denominator[Times@@primeMS[n]/Plus@@primeMS[n]], {n, 2, 100}]

CROSSREFS

Denominator of A003963(n)/A056239(n).

Positions of ones are A326149.

Cf. A057567, A057568, A112798, A301987, A325037, A325042, A325044, A326150, A326151, A326153, A326155, A326156, A326158.

Sequence in context: A049994 A135732 A322584 * A306248 A327513 A327530

Adjacent sequences:  A326151 A326152 A326153 * A326155 A326156 A326157

KEYWORD

nonn,frac

AUTHOR

Gus Wiseman, Jun 09 2019

STATUS

approved

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Last modified October 20 05:49 EDT 2019. Contains 328247 sequences. (Running on oeis4.)