OFFSET
1,2
COMMENTS
Number of terms of A257691 that divide n.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..25000
FORMULA
MATHEMATICA
q[n_] := DivisorSum[n, DigitCount[#, 2, 1] &] <= 2*DigitCount[n, 2, 1]; a[n_] := DivisorSum[n, 1 &, q[#] &]; Array[a, 100] (* Amiram Eldar, Jul 20 2023 *)
PROG
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Nov 10 2017
STATUS
approved