A353479 - OEIS

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A353479

a(n) = 1 if n is a semiprime of the form 4k+3, otherwise 0.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1`
	LINKS	`Antti Karttunen, Table of n, a(n) for n = 1..65537` `Index entries for characteristic functions`
	FORMULA	`a(n) = [A001222(n) == 2] * && [A010873(n) == 3], where [ ] are the Iverson brackets.` `a(n) = A353480(n) - A353477(n).` `a(n) = A280710(n) * A342025(n) = A353480(n) * A342025(n).`
	PROG	`(PARI) A353479(n) = ((2==bigomega(n)) && (3==(n%4)));`
	CROSSREFS	`Characteristic function of A080774.` `Cf. A001222, A010873, A064911, A280710, A342025, A353477, A353478, A353480.` `Sequence in context: A011729 A297044 A296213 * A360111 A359162 A327932` `Adjacent sequences: A353476 A353477 A353478 * A353480 A353481 A353482`
	KEYWORD	`nonn`
	AUTHOR	`Antti Karttunen, Apr 22 2022`
	STATUS	`approved`

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Last modified February 28 14:32 EST 2023. Contains 360738 sequences. (Running on oeis4.)