A088469 - OEIS

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A088469

Number of distinct dismal prime divisors of n.

0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 17, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 15, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 13, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,11`
	COMMENTS	`a(n) is the number of dismal primes p that are dismal divisors of n. (Multiplicity is not taken into account. Each prime is counted at most once.)`
	LINKS	`D. Applegate, C program for dismal arithmetic and number theory` `D. Applegate, M. LeBrun and N. J. A. Sloane, Dismal Arithmetic` `Index entries for sequences related to dismal arithmetic`
	EXAMPLE	`10 = 9*90 and 90 is prime. 90 is the only prime divisor of 10, so a(10) = 1.`
	CROSSREFS	`Cf. A088471, A088472, A087097.` `Sequence in context: A185685 A144692 A176728 * A089170 A040292 A040293` `Adjacent sequences: A088466 A088467 A088468 * A088470 A088471 A088472`
	KEYWORD	`nonn`
	AUTHOR	`David Applegate (david(AT)research.att.com), Nov 11 2003`

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Last modified February 17 08:21 EST 2012. Contains 205998 sequences.