OFFSET
1,1
COMMENTS
Previous name was "Sum of the middle pair in the n-term sequence 2, 3, 5, ..., prime(n)." - Jon E. Schoenfield, Oct 12 2015
The bisections are the doubled primes (A100484) and the sums of adjacent primes (A001043). - R. J. Mathar, Sep 11 2011
LINKS
Paolo Xausa, Table of n, a(n) for n = 1..10000
FORMULA
a(2n-1) = 2 prime(n), a(2n) = prime(n) + prime(n+1), n = 1,2,... - Zak Seidov, Jan 15 2014
a(n) = 2*A063934(n-1) for n>2. - Michel Marcus, Oct 13 2015
EXAMPLE
4 = sumtwice(2); 5 = sum(2,3); 6 = 2, sumtwice(3), 5, 7; 8 = 2, sum(3,5), 7, 11;
MAPLE
A144043 := proc(n) ithprime(ceil((n+1)/2))+ithprime(ceil(n/2)) ; end proc: # R. J. Mathar, Sep 11 2011
MATHEMATICA
With[{p=Prime[Range[50]]}, Riffle[2p, ListConvolve[{1, 1}, p]]] (* Paolo Xausa, Nov 02 2023 *)
PROG
(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
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Raul Rato (rtrato(AT)yahoo.com), Sep 08 2008
EXTENSIONS
Removed initial terms that regarded 1 as a prime. - R. J. Mathar, Sep 11 2011
Comments edited by Zak Seidov, Jan 15 2014
Name changed (based on formula from Zak Seidov) by Jon E. Schoenfield, Oct 12 2015
STATUS
approved