OFFSET
1,4
COMMENTS
LINKS
FORMULA
MATHEMATICA
a[n_] := DivisorSum[n, DigitCount[#, 2, 1] &, # < n &]; Array[a, 100] (* Amiram Eldar, Jul 20 2023 *)
PROG
(PARI) A292257(n) = sumdiv(n, d, (d<n)*hammingweight(d));
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Oct 04 2017
STATUS
approved