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A102724
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Sum of the first n pairs of consecutive primes (for example, a(3) = (2+3) + (3+5) + (5+7) = 25).
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3
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5, 13, 25, 43, 67, 97, 133, 175, 227, 287, 355, 433, 517, 607, 707, 819, 939, 1067, 1205, 1349, 1501, 1663, 1835, 2021, 2219, 2423, 2633, 2849, 3071, 3311, 3569, 3837, 4113, 4401, 4701, 5009, 5329, 5659, 5999, 6351, 6711, 7083, 7467, 7857, 8253, 8663, 9097
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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a(n) = 2sum(prime(i), i = 1 .. n) - (2 + prime(n)). - Alonso del Arte, Apr 21 2016
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EXAMPLE
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a(1) = 5 = (2+3).
a(2) = 13 = (2+3) + (3+5).
a(3) = 25 = (2+3) + (3+5) + (5+7).
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MATHEMATICA
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Table[Sum[Prime[i] + Prime[i + 1], {i, n}], {n, 47}] (* Ray Chandler, Feb 12 2005 *)
Table[2Sum[Prime[i], {i, n}] - (2 + Prime[n]), {n, 2, 50}] (* Alonso del Arte, Apr 26 2016 *)
Accumulate[Total/@Partition[Prime[Range[50]], 2, 1]] (* Harvey P. Dale, Apr 13 2019 *)
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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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EXTENSIONS
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STATUS
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approved
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