A128630 - OEIS

This site is supported by donations to The OEIS Foundation.

A128630

Let gpf(1)=1 and gpf(n)=greatest prime factor of n, n>1. Then a(n)=minimum over partitions of n of the sum of gpf of the parts.

1, 2, 3, 2, 3, 3, 4, 2, 3, 4, 5, 3, 4, 5, 5, 2, 3, 3, 4, 4, 5, 5, 6, 3, 4, 5, 3, 4, 5, 5, 5, 2, 3, 4, 5, 3, 4, 5, 6, 4, 5, 6, 5, 5, 5, 6, 7, 3, 4, 5, 6, 5, 6, 3, 4, 5, 6, 5, 5, 5, 6, 5, 6, 2, 3, 4, 5, 4, 5, 5, 6, 3, 4, 5, 5, 5, 6, 6, 7, 4, 3, 4, 5, 6, 5, 5, 6, 5, 5, 5, 5, 6, 6, 7, 7, 3, 4, 5, 6, 5, 6, 6, 7, 5, 6 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`1,2`
	LINKS	`Table of n, a(n) for n=1..105.`
	EXAMPLE	`a(5)=3 because gpf(5)=5, gpf(4)+gpf(1)=3, gpf(3)+gpf(2)=5, gpf(3)+2gpf(1)=5, 2gpf(2)+gpf(1)=5, gpf(2)+3gpf(1)=5, 5gpf(1)=5.`
	CROSSREFS	`Cf. A128631.` `Sequence in context: A137467 A078627 A106370 * A086389 A128622 A026256` `Adjacent sequences: A128627 A128628 A128629 * A128631 A128632 A128633`
	KEYWORD	`nonn`
	AUTHOR	`Logan Kleinwaks (kleinwaks(AT)alumni.princeton.edu), Mar 15 2007`
	STATUS	`approved`

Content is available under The OEIS End-User License Agreement .

Last modified May 23 17:52 EDT 2013. Contains 225611 sequences.