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A210998 Composite numbers that are in the gap between an even-indexed prime and an odd-indexed prime. 2
4, 8, 9, 10, 14, 15, 16, 20, 21, 22, 30, 38, 39, 40, 44, 45, 46, 54, 55, 56, 57, 58, 62, 63, 64, 65, 66, 72, 80, 81, 82, 90, 91, 92, 93, 94, 95, 96, 102, 108, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 132, 133, 134, 135, 136 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..58.

EXAMPLE

Illustration of initial terms of three sequences:

A210998:       4,         8, 9, 10,             14, 15, 16

A000040: 2, 3,    5,    7,          11,     13,

A210999:             6,                 12,

MATHEMATICA

Select[Range[4, 200], Not[PrimeQ[#]] && EvenQ[PrimePi[#]] &] (* Alonso del Arte, Sep 26 2012 *)

CROSSREFS

Cf. A002808, A014689, A031215, A031368, A073170, A210999.

Sequence in context: A080970 A288862 A274584 * A205524 A125493 A164923

Adjacent sequences:  A210995 A210996 A210997 * A210999 A211000 A211001

KEYWORD

nonn,easy

AUTHOR

Omar E. Pol, Sep 26 2012

STATUS

approved

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Last modified November 21 16:04 EST 2019. Contains 329371 sequences. (Running on oeis4.)