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A172188
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Partial sums of primes of the form 3*k-1.
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2
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2, 7, 18, 35, 58, 87, 128, 175, 228, 287, 358, 441, 530, 631, 738, 851, 982, 1119, 1268, 1435, 1608, 1787, 1978, 2175, 2402, 2635, 2874, 3125, 3382, 3645, 3914, 4195, 4488, 4799, 5116, 5463, 5816, 6175, 6558, 6947, 7348, 7767, 8198, 8641, 9090, 9551, 10018
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OFFSET
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1,1
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LINKS
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EXAMPLE
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a(1)=3*1-1=2, a(2)=2+3*2-1=7.
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MAPLE
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A003627 := proc(n) if n <= 2 then op(n, [2, 5]) ; else for a from procname(n-1)+2 by 2 do if isprime(a) and (a mod 3) =2 then return a ; end if; end do: end if; end proc:
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MATHEMATICA
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Accumulate[Select[Prime[Range[100]], IntegerQ[(#+1)/3]&]] (* Harvey P. Dale, Apr 04 2011 *)
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CROSSREFS
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KEYWORD
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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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