OFFSET
1,2
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = Sum_{k=1..n} A062758(k). - Michel Marcus, May 03 2022
EXAMPLE
For n = 4, A007955(n) = b(n): a(4) = b(1)^2 + b(2)^2 + b(3)^2 + b(4)^2 = 1^2 + 2^2 + 3^2 + 8^2 = 78.
MATHEMATICA
Accumulate@ Array[#^DivisorSigma[0, #] &, 29] (* Michael De Vlieger, May 03 2022 *)
PROG
(PARI) a(n) = sum(k=1, n, k^numdiv(k)); \\ Michel Marcus, May 03 2022
(Python)
from sympy import divisor_count
from itertools import count, islice
def agen():
an = 1
for k in count(2):
yield an
an += k**divisor_count(k)
print(list(islice(agen(), 29))) # Michael S. Branicky, May 03 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Apr 02 2010
EXTENSIONS
a(27) and beyond from Michael S. Branicky, May 03 2022
STATUS
approved