A323153 a(n) = 1 if n is either a prime or a perfect number, 0 otherwise.

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

Offset

1

Comments

Characteristic function of A053813.

Differs from A323152 at positions n = 1, 120, 672, 30240, 32760, ...

Links

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

Index entries for characteristic functions

Prog

(PARI) A323153(n) = ((n>1)&&!(n%sumdiv(n, d, (d<n)*d)));

Crossrefs

Cf. A000040, A000396, A053813, A053814, A323152.

Sequence in context: A228039 A163532 A014578 * A288861 A030190 A377870

Adjacent sequences: A323150 A323151 A323152 * A323154 A323155 A323156

Keyword

nonn

Author

Antti Karttunen, Jan 09 2019

Status

approved