id:A087032 - OEIS Search Results

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a(n)=1/0 if 2p-n is prime/composite, where p is the smallest prime > n.

+0
2

1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`There is no subsequence of two ones; number of zeros in each group is odd, see A087033`
	FORMULA	`a(n)=1/0 if A087030(n) is prime/composite.`
	EXAMPLE	`a(1)=1 because the smallest prime > 1 is 2 and 2*2-1=3 is prime.`
	MATHEMATICA	`bb={}; Do[bb={bb, If[PrimeQ[2(Prime[PrimePi[n]+1])-n], 1, 0]}, {n, 1000}]; Flatten[bb]`
	CROSSREFS	`Cf. A087033.` `Sequence in context: A015549 A015829 A016334 this_sequence A102242 A005369 A108340` `Adjacent sequences: A087029 A087030 A087031 this_sequence A087033 A087034 A087035`
	KEYWORD	`easy,nonn`
	AUTHOR	`Zak Seidov (zakseidov(AT)yahoo.com), Jul 31 2003`

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Last modified July 25 07:41 EDT 2008. Contains 142293 sequences.

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