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A168141 a(n) = PrimePi(n+1) - PrimePi(n-2). 1
1, 2, 2, 2, 1, 2, 1, 1, 0, 1, 1, 2, 1, 1, 0, 1, 1, 2, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 2, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 2, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 2, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 2, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 2, 1, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..105.

MAPLE

A168141 := proc(n) numtheory[pi](n+1)-numtheory[pi](n-2) ; end proc: seq(A168141(n), n=1..120) ; # R. J. Mathar, Nov 19 2009

CROSSREFS

Cf. A000720, A090406.

Sequence in context: A212119 A096831 A191516 * A232654 A034095 A105971

Adjacent sequences:  A168138 A168139 A168140 * A168142 A168143 A168144

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Nov 19 2009

STATUS

approved

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Last modified December 11 01:07 EST 2019. Contains 329910 sequences. (Running on oeis4.)