A294935 Characteristic function for nonabundant numbers (A263837): a(n) = 1 if A001065(n) <= n, 0 otherwise.

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

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for characteristic functions.

Index entries for sequences related to sums of divisors.

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. A001065, A033879, A294934, A294936, A294937.

Cf. A263837 (positions of ones), A005101 (of zeros).

Sequence in context: A353799 A123927 A089829 * A242902 A196368 A178788

Adjacent sequences: A294932 A294933 A294934 * A294936 A294937 A294938

Keyword

nonn

Author

Antti Karttunen, Nov 12 2017

Status

approved