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A072165 Values of Moebius function of the products of two (not necessarily distinct) primes (semiprimes or 2-almost primes, A001358). 1
0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Characteristic function for numbers n such that A001358(n) is not a square. - Antti Karttunen, Oct 04 2017

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..3001

Kimberly Schneider, Moebius function.

Index entries for characteristic functions

FORMULA

a(n) = A008683(A001358(n)). - Antti Karttunen, Oct 04 2017

EXAMPLE

For n = 2995, A001358(2995) = 11449 = 107^2, and as Moebius mu is zero for squares, we have a(2995) = 0. - Antti Karttunen, Oct 04 2017

MAPLE

semiprimes := proc(d_n) local a, i; a := [ ]; for i from 1 to d_n do if((tau(i) = 3) or ((mobius(i) <> 0) and (tau(i) = 4))) then a := [ op(a), mobius(i) ]; fi; od: RETURN(a); end;

CROSSREFS

Cf. A001358, A008683.

Sequence in context: A288864 A115971 A320007 * A072608 A295304 A171386

Adjacent sequences:  A072162 A072163 A072164 * A072166 A072167 A072168

KEYWORD

easy,nonn

AUTHOR

Jani Melik, Jun 28 2002

EXTENSIONS

More terms from Antti Karttunen, Oct 04 2017

STATUS

approved

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Last modified August 1 21:02 EDT 2021. Contains 346408 sequences. (Running on oeis4.)