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A144043
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a(2n-1) = 2*prime(n), a(2n) = prime(n) + prime(n+1).
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1
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4, 5, 6, 8, 10, 12, 14, 18, 22, 24, 26, 30, 34, 36, 38, 42, 46, 52, 58, 60, 62, 68, 74, 78, 82, 84, 86, 90, 94, 100, 106, 112, 118, 120, 122, 128, 134, 138, 142, 144, 146, 152, 158, 162, 166, 172, 178, 186, 194, 198, 202, 204
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OFFSET
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1,1
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COMMENTS
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Previous name was "Sum of the middle pair in the n-term sequence 2, 3, 5, ..., prime(n)." - Jon E. Schoenfield, Oct 12 2015
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LINKS
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FORMULA
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a(2n-1) = 2 prime(n), a(2n) = prime(n) + prime(n+1), n = 1,2,... - Zak Seidov, Jan 15 2014
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EXAMPLE
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4 = sumtwice(2); 5 = sum(2,3); 6 = 2, sumtwice(3), 5, 7; 8 = 2, sum(3,5), 7, 11;
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MAPLE
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A144043 := proc(n) ithprime(ceil((n+1)/2))+ithprime(ceil(n/2)) ; end proc: # R. J. Mathar, Sep 11 2011
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MATHEMATICA
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With[{p=Prime[Range[50]]}, Riffle[2p, ListConvolve[{1, 1}, p]]] (* Paolo Xausa, Nov 02 2023 *)
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PROG
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(MATLAB) clc clear all aP= [primes(1000)]; qN= numel(aP); kL=[]; %init empty result for nn= 1:qN %Loop to sum the central pairs auxT= ceil((nn+1)/2); auxL= ceil(nn/2); kL= [kL; aP(auxL)+aP(auxT)]; end kL %kL is the result
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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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Raul Rato (rtrato(AT)yahoo.com), Sep 08 2008
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EXTENSIONS
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Removed initial terms that regarded 1 as a prime. - R. J. Mathar, Sep 11 2011
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STATUS
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approved
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