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A128233
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Average of p(n) and p(p(n)), where p(k) is the k-th prime.
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1
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4, 8, 12, 21, 27, 38, 43, 53, 69, 79, 97, 110, 117, 129, 147, 168, 172, 199, 212, 220, 240, 257, 275, 303, 324, 333, 347, 354, 365, 418, 435, 455, 468, 504, 514, 538, 565, 579, 602, 621, 634, 672, 682, 699, 708, 754, 816, 830, 838, 852, 869, 882, 924, 939, 966
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OFFSET
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2,1
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LINKS
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EXAMPLE
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a(4)=12 because p(4)=7 and p(7)=17.
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MAPLE
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a:=n->(ithprime(n)+ithprime(ithprime(n)))/2: seq(a(n), n=2..70);
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MATHEMATICA
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Table[Mean[{Prime[n], Prime[Prime[n]]}], {n, 2, 60}] (* Harvey P. Dale, Jul 30 2020 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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