id:A085102 - OEIS Search Results

Search: id:A085102

Displaying 1-1 of 1 results found.

page 1

Go on adding the divisors of n starting from n in decreasing order until one gets a prime. a(n) = this prime, or 0 if no prime is obtained.

+0
2

0, 2, 3, 7, 5, 11, 7, 0, 13, 17, 11, 0, 13, 23, 23, 31, 17, 0, 19, 41, 31, 0, 23, 59, 31, 41, 0, 53, 29, 61, 31, 0, 47, 53, 47, 0, 37, 59, 0, 83, 41, 0, 43, 83, 0, 71, 47, 0, 0, 0, 71, 97, 53, 0, 71, 113, 79, 89, 59, 137, 61, 0, 103, 127, 83, 0, 67, 0, 0, 0, 71, 179, 73, 113, 0, 137, 0 (list; graph; listen)

	OFFSET	`1,2`
	COMMENT	`1. a(p) = p, where p is a prime, by definition. 2. If 2^k -1 is a Merssene's prime then a(2^(k-1)) = 2^k -1 else a(2^(k-1))= 0. 3. a(p^(2k+1)) = 0, if p is prime.`
	EXAMPLE	`a(28) = 53 because 28+14+7+4 = 53 is prime.`
	CROSSREFS	`Cf. A085103.` `Sequence in context: A060203 A131880 A045790 this_sequence A087572 A085107 A034694` `Adjacent sequences: A085099 A085100 A085101 this_sequence A085103 A085104 A085105`
	KEYWORD	`nonn`
	AUTHOR	`Amarnath Murthy and Meenakshi Srikanth (amarnath_murthy(AT)yahoo.com), Jul 03 2003`
	EXTENSIONS	`Corrected and extended by David Wasserman (wasserma(AT)spawar.navy.mil), Jan 26 2005`

page 1

Search completed in 0.002 seconds

Last modified July 24 12:00 EDT 2008. Contains 142294 sequences.

AT&T Labs Research