OFFSET
1,1
COMMENTS
The corresponding primes are 5, 17, 83, 2089, 2341, 2861, 42503239, 3338549, 276977179, 2239777822987, ...
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..96
EXAMPLE
3 is a term since 1 + 1/2 + 1/3 = 11/6, the fractional part of 11/6 is 5/6 and its numerator, 5, is prime.
5 is a term since 1 + 1/2 + 1/3 + 1/4 + 1/5 = 137/60, the fractional part of 137/60 is 17/60 and its numerator, 17, is prime.
MATHEMATICA
s = 0; seq = {}; Do[s += 1/n; If[PrimeQ @ Numerator @ FractionalPart[s], AppendTo[seq, n]], {n, 1, 2500}]; seq
PROG
(Python)
from sympy import harmonic, isprime
A348017_list = [k for k in range(10**3) if isprime((lambda x: x.p % x.q)(harmonic(k)))] # Chai Wah Wu, Sep 26 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Sep 24 2021
STATUS
approved