The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A353556 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A353556

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

#11 by Harvey P. Dale at Fri Jan 12 17:32:41 EST 2024

STATUS

editing

approved

#10 by Harvey P. Dale at Fri Jan 12 17:32:39 EST 2024

MATHEMATICA

Table[If[EvenQ[n]&&OddQ[PrimeOmega[n]], 1, 0], {n, 150}] (* Harvey P. Dale, Jan 12 2024 *)

STATUS

approved

editing

#9 by Michael De Vlieger at Mon May 02 11:13:15 EDT 2022

STATUS

proposed

approved

#8 by Antti Karttunen at Mon May 02 03:14:11 EDT 2022

STATUS

editing

proposed

#7 by Antti Karttunen at Mon May 02 03:08:14 EDT 2022

LINKS

Antti Karttunen, <a href="/A353556/b353556.txt">Table of n, a(n) for n = 1..65537</a>

STATUS

approved

editing

#6 by Michael De Vlieger at Sun May 01 23:05:01 EDT 2022

STATUS

proposed

approved

#5 by Antti Karttunen at Sun May 01 08:45:46 EDT 2022

STATUS

editing

proposed

#4 by Antti Karttunen at Sun May 01 08:37:23 EDT 2022

CROSSREFS

Cf. A059841, A066829.

Cf. A059841, A066829, A353555, A353557, A353558.

Discussion

Sun May 01

08:45

Antti Karttunen: Longish data section because this section tends to get crowded (to better differentiate from the neighbours).

#3 by Antti Karttunen at Sun May 01 08:30:35 EDT 2022

FORMULA

a(n) = A059841(n) - A353555(n).

a(n) = A066829(n) - A353558(n).

#2 by Antti Karttunen at Sun May 01 08:18:54 EDT 2022

NAME

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

DATA

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

OFFSET

1

LINKS

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

FORMULA

a(n) = A059841(n) * A066829(n).

PROG

(PARI) A353556(n) = ((!(n%2))&&(bigomega(n)%2));

CROSSREFS

Cf. A059841, A066829.

Characteristic function of A046470.

KEYWORD

allocated

nonn

AUTHOR

Antti Karttunen, May 01 2022

STATUS

approved

editing