OFFSET
1,2
LINKS
Michel Marcus, Table of n, a(n) for n = 1..300
MAPLE
a:= n-> add(add(i, i=Bits[Split](d)), d=numtheory[divisors](2^n-1)):
seq(a(n), n=1..60); # Alois P. Heinz, May 17 2022
MATHEMATICA
a[n_] := Total[DigitCount[Divisors[2^n - 1], 2, 1]]; Array[a, 60] (* Amiram Eldar, May 17 2022 *)
PROG
(PARI) a(n) = sumdiv(2^n-1, d, hammingweight(d));
(Python 3.10+)
# if python version < 3.10, replace d.bitcount() with bin(d).count('1')
from sympy import divisors
def A354112(n): return sum(d.bit_count() for d in divisors(2**n-1, generator=True)) # Chai Wah Wu, May 17 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Michel Marcus, May 17 2022
STATUS
approved