OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
For n = 6; pi(6) = 36; a(n) = (1/2)*36*37 = 666.
MATHEMATICA
# (#+1)/2&/@Array[Times@@Divisors[#]&, 40] (* Harvey P. Dale, Oct 05 2012 *)
PROG
(Python)
from math import isqrt
from sympy import divisor_count
def A184390(n): return (m:=((isqrt(n) if (c:=divisor_count(n)) & 1 else 1)*n**(c//2)))*(m+1)//2 # Chai Wah Wu, Jun 25 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jan 12 2011
STATUS
approved