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A163656 Arithmetic mean of the n-th and (n+1)st twin prime member A001097. 3
4, 6, 9, 12, 15, 18, 24, 30, 36, 42, 51, 60, 66, 72, 87, 102, 105, 108, 123, 138, 144, 150, 165, 180, 186, 192, 195, 198, 213, 228, 234, 240, 255, 270, 276, 282, 297, 312, 330, 348, 384, 420, 426, 432, 447, 462, 492, 522, 546, 570, 585, 600, 609, 618, 630, 642 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = (A001097(n) + A001097(n+1))/2.

EXAMPLE

a(1) = 4 = (3+5)/2.

MATHEMATICA

t = Select[Prime[Range[500]], PrimeQ[# - 2] || PrimeQ[# + 2] &]; (Most[t] + Rest[t])/2 (* T. D. Noe, Aug 07 2012 *)

CROSSREFS

Cf. A014574 (bisection).

Sequence in context: A162735 A024675 A274135 * A100915 A144922 A298864

Adjacent sequences:  A163653 A163654 A163655 * A163657 A163658 A163659

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Aug 02 2009

EXTENSIONS

35 replaced by 36 - R. J. Mathar, Aug 06 2009

STATUS

approved

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Last modified May 25 00:03 EDT 2022. Contains 354047 sequences. (Running on oeis4.)