OFFSET
1,4
COMMENTS
The reciprocal sum of (y_1, ..., y_k) is 1/y_1 + ... + 1/y_k. The Heinz number of an integer partition (y_1, ..., y_k) is prime(y_1) * ... * prime(y_k).
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10000
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537
FORMULA
If n = Product prime(x_i)^y_i is the prime factorization of n, then a(n) is the numerator of Sum y_i/x_i.
MATHEMATICA
Table[Sum[pr[[2]]/PrimePi[pr[[1]]], {pr, If[n==1, {}, FactorInteger[n]]}], {n, 100}]//Numerator
PROG
(PARI) A318573(n) = { my(f=factor(n)); numerator(sum(i=1, #f~, f[i, 2]/primepi(f[i, 1]))); }; \\ Antti Karttunen, Nov 17 2019
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Gus Wiseman, Aug 29 2018
EXTENSIONS
More terms from Antti Karttunen, Nov 17 2019
STATUS
approved