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A294934 Characteristic function for deficient numbers (A005100): a(n) = 1 if A001065(n) < n, 0 otherwise. 17
1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 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, 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 (list; graph; refs; listen; history; text; internal format)
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 - A294936(n).

a(n) = 1 - sign(floor(sigma(n)/(2*n))), where sigma is the sum of the divisors of n (A000203). - Wesley Ivan Hurt, Oct 01 2020

MATHEMATICA

Table[1 - Sign[Floor[DivisorSigma[1, n]/(2 n)]], {n, 100}] (* Wesley Ivan Hurt, Oct 02 2020 *)

CROSSREFS

Cf. A001065, A033879, A294935, A294936, A294937.

Cf. A005100 (positions of 1's), A023196 (of 0's).

Cf. A000203 (sigma).

Sequence in context: A345009 A071040 A336834 * A174340 A300294 A071041

Adjacent sequences:  A294931 A294932 A294933 * A294935 A294936 A294937

KEYWORD

nonn,easy

AUTHOR

Antti Karttunen, Nov 12 2017

STATUS

approved

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Last modified August 5 18:22 EDT 2021. Contains 346488 sequences. (Running on oeis4.)