id:A121611 - OEIS Search Results

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Number of ways to express n as an average of three distinct primes.

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0, 0, 0, 1, 1, 2, 2, 2, 3, 2, 4, 3, 6, 3, 6, 3, 8, 3, 10, 3, 12, 5, 13, 5, 14, 5, 17, 4, 21, 4, 22, 4, 21, 6, 23, 5, 27, 7, 32, 5, 36, 5, 35, 7, 34, 5, 36, 7, 43, 5, 46, 8, 47, 8, 44, 5, 52, 6, 55, 6, 61, 8, 58, 8, 57, 9, 67, 8, 71, 7, 79, 7, 72, 9, 69, 6, 76, 7, 83, 9, 94, 9, 91, 9, 89, 8, 94, 8 (list; graph; listen)

	OFFSET	`1,6`
	COMMENT	`For odd n's a(n) are much larger than a(n-/+1). Cf. A061357 = number of ways n can be expressed as the mean of two distinct primes, A061357 = number of ways the even integer 2n can be written as the sum of two primes for all even integers >6.`
	EXAMPLE	`a(4)=1 because 4 = (2+3+7)/3 (1 way),` `a(6)=2 because 6 = (2+3+13)/3 = (2+5+11)/3 (2 ways)` `a(9)=3 because 9 = (3+5+19)/3 = (3+7+17)/3 = (3+11+13)/3 (3 ways)` `a(11)=4 because 11 = (3+7+23)/3 = (3+11+19)/3 = (3+13+17)/3 = (5+11+19)/3 (4 ways), etc.`
	CROSSREFS	`Cf. A061357, A061357.` `Sequence in context: A029210 A035433 A029199 this_sequence A046798 A157231 A104239` `Adjacent sequences: A121608 A121609 A121610 this_sequence A121612 A121613 A121614`
	KEYWORD	`nonn`
	AUTHOR	`Zak Seidov (zakseidov(AT)yahoo.com), Sep 08 2006`

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Last modified November 22 20:51 EST 2009. Contains 167312 sequences.

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