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A174933 a(n) = Sum_{d|n} A007955(d) * A000027(d) = Sum_{d|n} A007955(d) * (d), where A007955(m) = product of divisors of m. 2
1, 5, 10, 37, 26, 230, 50, 549, 253, 1030, 122, 20998, 170, 2798, 3410, 16933, 290, 105449, 362, 161062, 9320, 10774, 530, 7984134, 3151, 17750, 19936, 617486, 842, 24304630, 962, 1065509, 36068, 39598, 42950, 362923273, 1370, 55238, 59498, 102561574 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
For n = 4, A007955(n) = b(n): a(4) = b(1)*1 + b(2)*2 + b(4)*4 = 1*1 + 2*2 + 8*4 = 37.
PROG
(PARI) a(n)={sumdiv(n, d, vecprod(divisors(d))*d)} \\ Andrew Howroyd, Jan 05 2020
(Magma) [&+[&*Divisors(d)*d:d in Divisors(n)]:n in [1..40]]; // Marius A. Burtea, Jan 05 2020
(Python)
from math import isqrt
from sympy import divisor_count, divisors
def A174933(n): return sum(isqrt(d)**(c+2) if (c:=divisor_count(d)) & 1 else d**(c//2+1) for d in divisors(n, generator=True)) # Chai Wah Wu, Jun 25 2022
CROSSREFS
Cf. A007955.
Sequence in context: A326232 A189732 A307607 * A270219 A270276 A271604
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Apr 02 2010
EXTENSIONS
Terms a(31) and beyond from Andrew Howroyd, Jan 05 2020
STATUS
approved

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Last modified March 3 00:25 EST 2024. Contains 370499 sequences. (Running on oeis4.)