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A024675
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Average of two consecutive odd primes.
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60
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4, 6, 9, 12, 15, 18, 21, 26, 30, 34, 39, 42, 45, 50, 56, 60, 64, 69, 72, 76, 81, 86, 93, 99, 102, 105, 108, 111, 120, 129, 134, 138, 144, 150, 154, 160, 165, 170, 176, 180, 186, 192, 195, 198, 205, 217, 225, 228, 231, 236, 240, 246, 254, 260, 266, 270, 274, 279, 282, 288, 300
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Sometimes called interprimes.
Where local maxima of A072681 occur: A072681(a(n))=A074927(n+1). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 04 2009]
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LINKS
| T. D. Noe, Table of n, a(n) for n=1..10000
Eric Weisstein's World of Mathematics, Interprime
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FORMULA
| a(n) = A001043(n+1)/2. - Omar E. Pol, Feb 02 2012
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MAPLE
| seq( ( (ithprime(x)+ithprime(x+1))/2 ), x=2..40);
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MATHEMATICA
| Plus @@@ Partition[Table[Prime[n], {n, 2, 100}], 2, 1]/2
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PROG
| (PARI) for(X=2, 50, print((prime(X)+prime(X+1))/2)) - Hauke Worpel (thebigh(AT)outgun.com), May 08 2008
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CROSSREFS
| Cf. A072568, A072569. Bisections give A058296, A079424.
Sequence in context: A171845 A157124 A162735 * A163656 A100915 A144922
Adjacent sequences: A024672 A024673 A024674 * A024676 A024677 A024678
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KEYWORD
| nonn,nice,easy,changed
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AUTHOR
| Clark Kimberling (ck6(AT)evansville.edu)
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