A073784 - OEIS

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A073784

Number of primes between successive composite numbers.

1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	EXAMPLE	`a(7) = 0 since there are no primes between the 7th and the 8th composites, (14 and 15).`
	MATHEMATICA	`Composite[n_Integer] := FixedPoint[n + PrimePi[ # ] + 1 &, n + PrimePi[n] + 1]; Table[ PrimePi[Composite[n + 1]] - PrimePi[Composite[n]], {n, 105}] (from Robert G. Wilson v Dec 20 2004)`
	CROSSREFS	`a(n) = A073783(n) - 1` `a(n) = A002808(n+1) - A002808(n) - 1` `Also first differences of A073425.` `Sequence in context: A191747 A133081 A125999 * A128130 A133872 A068434` `Adjacent sequences: A073781 A073782 A073783 * A073785 A073786 A073787`
	KEYWORD	`easy,nonn`
	AUTHOR	`Lior Manor (lior.manor(AT)gmail.com) Aug 11 2002`

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Last modified February 14 23:16 EST 2012. Contains 205687 sequences.