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A323153 a(n) = 1 if n is either a prime or a perfect number, 0 otherwise. 2
0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1
COMMENTS
Characteristic function of A053813.
Differs from A323152 at positions n = 1, 120, 672, 30240, 32760, ...
LINKS
PROG
(PARI) A323153(n) = ((n>1)&&!(n%sumdiv(n, d, (d<n)*d)));
CROSSREFS
Sequence in context: A228039 A163532 A014578 * A288861 A030190 A353471
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 09 2019
STATUS
approved

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Last modified March 29 00:26 EDT 2024. Contains 371264 sequences. (Running on oeis4.)