OFFSET
1,1
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = Sum_{d|n} prime(d)*prime(n/d). - Ilya Gutkovskiy, Mar 11 2018
MATHEMATICA
Table[DivisorSum[n, Prime[n/#]*Prime[#] &], {n, 80}] (* Wesley Ivan Hurt, Jun 22 2024 *)
PROG
(PARI) a(n) = sumdiv(n, d, prime(d)*prime(n/d)); \\ Michel Marcus, Mar 11 2018
(Python)
from sympy import divisors, prime, primerange
def dirichlet(f, g, n): return sum(f[d] * g[n//d] for d in divisors(n))
def aupton(terms):
p = [0] + list(primerange(2, prime(terms)+1))
return [dirichlet(p, p, k) for k in range(1, terms+1)]
print(aupton(51)) # Michael S. Branicky, Apr 12 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved