The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A353672 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A353672

a(n) = 1 if n is an even number with an even number of distinct prime factors, otherwise 0.
(history; published version)

#9 by Michael De Vlieger at Wed May 04 08:29:37 EDT 2022

STATUS

proposed

approved

#8 by Antti Karttunen at Wed May 04 04:34:19 EDT 2022

STATUS

editing

proposed

#7 by Antti Karttunen at Wed May 04 04:19:40 EDT 2022

LINKS

Antti Karttunen, <a href="/A353672/b353672.txt">Table of n, a(n) for n = 1..65537</a>

STATUS

approved

editing

#6 by Michael De Vlieger at Tue May 03 23:25:31 EDT 2022

STATUS

proposed

approved

#5 by Antti Karttunen at Tue May 03 22:24:06 EDT 2022

STATUS

editing

proposed

#4 by Antti Karttunen at Tue May 03 21:45:53 EDT 2022

FORMULA

a(n) = A059841(n) - A353674(n).

#3 by Antti Karttunen at Tue May 03 20:36:56 EDT 2022

CROSSREFS

Cf. A001221, A059841, A092248, A353673, A353674, A353675.

Cf. also A353555.

#2 by Antti Karttunen at Tue May 03 16:47:40 EDT 2022

NAME

allocated for Antti Karttunena(n) = 1 if n is an even number with an even number of distinct prime factors, otherwise 0.

DATA

0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0

OFFSET

1

LINKS

<a href="/index/Ch#char_fns">Index entries for characteristic functions</a>

FORMULA

a(n) = [n is even] * [A001221(n) is even], where [ ] is the Iverson bracket.

a(n) = A059841(n) * (1-A092248(n)).

PROG

(PARI) A353672(n) = (!(n%2) && !(omega(n)%2));

CROSSREFS

Characteristic function of A098902.

Cf. A001221, A059841, A092248.

KEYWORD

allocated

nonn

AUTHOR

Antti Karttunen, May 03 2022

STATUS

approved

editing

#1 by Antti Karttunen at Tue May 03 16:23:41 EDT 2022

NAME

allocated for Antti Karttunen

KEYWORD

allocated

STATUS

approved