OFFSET
1,3
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
FORMULA
EXAMPLE
The 0-prepended prime indices of 100 are {0,1,1,3,3}, with differences (1,0,2,0), with mean 3/4, so a(100) = 3.
MATHEMATICA
prix[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
Table[If[n==1, 0, Numerator[Mean[Differences[Prepend[prix[n], 0]]]]], {n, 100}]
PROG
(PARI) A360614(n) = if(1==n, 0, my(u=primepi(vecmax(factor(n)[, 1]))); (u/gcd(u, bigomega(n)))); \\ Antti Karttunen, Oct 23 2023
KEYWORD
nonn,frac
AUTHOR
Gus Wiseman, Feb 19 2023
EXTENSIONS
Data section extended up to a(100) by Antti Karttunen, Oct 23 2023
STATUS
approved