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A058296
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Average of consecutive primes.
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5
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2, 4, 9, 15, 21, 30, 39, 45, 56, 64, 72, 81, 93, 102, 108, 120, 134, 144, 154, 165, 176, 186, 195, 205, 225, 231, 240, 254, 266, 274, 282, 300, 312, 324, 342, 351, 363, 376, 386, 399, 414, 426, 436, 446, 459, 465, 483, 495, 506, 522, 544, 560, 570, 582, 596
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OFFSET
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1,1
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COMMENTS
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2 together with average of odd primes taken two at a time without overlaps, i.e., 2 together with average of (3,5), (7,11), (13,17), etc. - Harvey P. Dale, Apr 09 2018
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LINKS
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FORMULA
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a(1)=2, a(n) = (p(2n-2) + p(2n-1))/2 for n>1, where p(i) is the i-th prime.
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MAPLE
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with(linalg): v := linalg[vector](100): v[1] := 2: for j from 2 to 100 do v[j] := (ithprime(2*j-2)+ithprime(2*j-1))/2: od: print(v);
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MATHEMATICA
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Join[{2}, Mean/@Partition[Prime[Range[2, 121]], 2]] (* Harvey P. Dale, Apr 09 2018 *)
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PROG
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(PARI) { write("b058296.txt", 1, " ", 2); p2=2; for (n=2, 20000, p1=nextprime(p2+1); p2=nextprime(p1+1); a=(p1+p2)/2; write("b058296.txt", n, " ", a); ); } \\ Harry J. Smith, May 30 2009
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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Donald Mills (dmills(AT)math.siu.edu), Feb 16 2003
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STATUS
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approved
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