id:A078809 - OEIS Search Results

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Number of divisors of the average of consecutive odd primes.

+0
1

3, 4, 3, 6, 4, 6, 4, 4, 8, 4, 4, 8, 6, 6, 8, 12, 7, 4, 12, 6, 5, 4, 4, 6, 8, 8, 12, 4, 16, 4, 4, 8, 15, 12, 8, 12, 8, 8, 10, 18, 8, 14, 8, 12, 4, 4, 9, 12, 8, 6, 20, 8, 4, 12, 8, 16, 4, 6, 8, 18, 18, 4, 16, 12, 15, 4, 12, 12, 8, 6, 6, 8, 8, 4, 4, 4, 8, 10, 12, 24, 8, 20, 6, 9, 4, 4, 8, 16, 8, 4, 8, 4 (list; graph; listen)

	OFFSET	`1,1`
	EXAMPLE	`The first pair of consecutive odd primes is 3,5, with average = 4 and tau(4) = 3. Hence a(1) = 3. The second pair of consecutive odd primes is 5,7, with average = 6 and tau(6) = 4, so a(2) = 4.`
	MATHEMATICA	`Table[DivisorSigma[0, (Prime[i] + Prime[i + 1])/2], {i, 2, 101}]`
	CROSSREFS	`Sequence in context: A104076 A021295 A061112 this_sequence A097857 A110738 A175028` `Adjacent sequences: A078806 A078807 A078808 this_sequence A078810 A078811 A078812`
	KEYWORD	`easy,nonn`
	AUTHOR	`Joseph L. Pe (Joseph_l_pe(AT)hotmail.com), Jan 11 2003`

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Last modified December 2 11:54 EST 2009. Contains 167921 sequences.

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