STATUS
reviewed
approved
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Revision History for A070889
(Bold, blue-underlined text is an addition; faded, red-underlined text is aShowing entries 1-10 | older changes
STATUS
proposed
reviewed
STATUS
editing
proposed
PROG
(Python)
from functools import lru_cache
from sympy import harmonic
@lru_cache(maxsize=None)
def f(n):
if n <= 1:
return 1
c, j = 1, 2
k1 = n//j
while k1 > 1:
j2 = n//k1 + 1
c += (harmonic(j-1)-harmonic(j2-1))*f(k1)
j, k1 = j2, n//j2
return c+harmonic(j-1)-harmonic(n)
def A070889(n): return f(n).denominator # Chai Wah Wu, Nov 03 2023
STATUS
approved
editing
STATUS
editing
approved
KEYWORD
frac,nonn,easy
STATUS
approved
editing
STATUS
reviewed
approved
STATUS
proposed
reviewed
STATUS
editing
proposed
PROG
(PARI: ) t = 0; v = []; for( n = 1, 30, t = t + mumoebius( n) / n; v = concat( v, denomdenominator( t))); v
STATUS
proposed
editing