login
A294935
Characteristic function for nonabundant numbers (A263837): a(n) = 1 if A001065(n) <= n, 0 otherwise.
10
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0
OFFSET
1
FORMULA
a(n) = 1 if A033879(n) >= 0, 0 otherwise.
a(n) = 1 - A294937(n).
MATHEMATICA
a[n_] := Boole[DivisorSigma[1, n] <= 2*n]; Array[a, 100] (* Amiram Eldar, Mar 14 2024 *)
CROSSREFS
Cf. A263837 (positions of ones), A005101 (of zeros).
Sequence in context: A353799 A123927 A089829 * A242902 A196368 A178788
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 12 2017
STATUS
approved