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A294902 Number of proper divisors of n that are in A175526. 9
0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 2, 0, 2, 0, 2, 0, 0, 0, 4, 0, 0, 1, 2, 0, 3, 0, 3, 0, 0, 0, 5, 0, 0, 0, 4, 0, 3, 0, 2, 2, 0, 0, 6, 0, 1, 0, 2, 0, 4, 0, 4, 0, 0, 0, 7, 0, 0, 2, 4, 0, 3, 0, 2, 0, 3, 0, 8, 0, 0, 1, 2, 0, 3, 0, 6, 2, 0, 0, 7, 0, 0, 0, 4, 0, 7, 0, 2, 0, 0, 0, 8, 0, 2, 2, 4, 0, 3, 0, 4, 3, 0, 0, 8, 0, 3, 0, 6, 0, 3, 0, 2, 2, 0, 0, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,12
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..25000
FORMULA
a(n) = Sum_{d|n, d<n} (1-A294905(d)).
a(n) = A294904(n) + A294905(n) - 1.
a(n) + A294901(n) = A032741(n).
MATHEMATICA
q[n_] := DivisorSum[n, DigitCount[#, 2, 1] &] > 2 * DigitCount[n, 2, 1]; a[n_] := DivisorSum[n, 1 &, # < n && q[#] &]; Array[a, 100] (* Amiram Eldar, Jul 20 2023 *)
PROG
(PARI)
A292257(n) = sumdiv(n, d, (d<n)*hammingweight(d));
A294905(n) = (A292257(n) <= hammingweight(n));
A294902(n) = sumdiv(n, d, (d<n)*(0==A294905(d)));
CROSSREFS
Cf. A000120, A032741, A175526, A292257, A294901, A294903, A294904, A294905.
Cf. also A294892.
Sequence in context: A112313 A297115 A337346 * A321516 A172246 A087893
Adjacent sequences: A294899 A294900 A294901 * A294903 A294904 A294905
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Nov 10 2017
STATUS
approved

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Last modified August 30 11:14 EDT 2024. Contains 375543 sequences. (Running on oeis4.)