A086712 - OEIS

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A086712

Number of times the n-th prime power can be written as an arithmetic mean of two other prime powers.

0, 1, 2, 2, 3, 3, 3, 4, 3, 4, 6, 6, 5, 5, 7, 8, 5, 6, 6, 7, 6, 8, 6, 8, 8, 7, 8, 10, 10, 9, 8, 9, 14, 8, 10, 11, 10, 12, 8, 11, 8, 12, 13, 12, 11, 11, 13, 13, 13, 13, 13, 11, 11, 14, 11, 13, 16, 12, 16, 14, 15, 16, 17, 13, 16, 15, 12, 18, 27, 15, 19, 18, 17, 15, 16, 15, 13, 18, 17, 15 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,3`
	LINKS	`Eric Weisstein's World of Mathematics, Prime Power`
	EXAMPLE	`n=7, A000961(7)=8=2^3: (3+13)/2=(A000961(3)+A000961(10))/2, (5+11)/2=(A000961(5)+A000961(9))/2 and (7+3^2)/2=(A000961(6)+A000961(8))/2: therefore a(7)=3.`
	CROSSREFS	`Cf. A000961, A071681.` `Sequence in context: A134674 A000121 A049846 * A125842 A029865 A072644` `Adjacent sequences: A086709 A086710 A086711 * A086713 A086714 A086715`
	KEYWORD	`nonn`
	AUTHOR	`Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Aug 01 2003`

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Last modified February 14 19:37 EST 2012. Contains 205663 sequences.